Biology How Life Works Volume 2, 2nd Edition By James Morris – Test Bank A+

Description

1. The discovery that DNA from killed virulent bacterial can transform live harmless bacteria into virulent forms means that DNA:
2. A) is double stranded.
3. B) is transcribed into RNA.
4. C) codes for proteins.
5. D) contains information that controls an organism’s traits.

1. If the Avery-MacLeod-McCarty transformation experiment was carried out in an RNA world, the transforming activity would be destroyed by:
2. A)
3. B)
4. C)
5. D)

1. Would a double-stranded DNA molecule carry more information than a single-stranded RNA molecule of the same length? Why?

1. A “googol” is the term given to the number 10100 (that is, the number 1 followed by 100 zeros). Given a double-stranded DNA molecule of length n base pairs, how big does n have to be to yield more than a googol of possible sequences?

1. A “googol” is the term given to the number 10100 (that is, the number 1 followed by 100 zeros). The DNA molecules in the chromosomes in a human sperm or egg contain approximately 3 × 109 (3 billion) base pairs. How many googol’s worth of genetic information could be encoded in human chromosomal DNA molecules?

1. Nonvirulent bacteria can still be transformed into virulent bacteria if it is combined with debris from heat-killed virulent bacteria that is first treated with: (Select all that apply.)
2. A)
3. B)
4. C)
5. D) no enzyme.

1. When a mixture of debris from killed virulent bacteria and live nonvirulent bacteria are injected into mice:
2. A) the mice are killed because the virulent bacteria are revived.
3. B) the mice survive because none of the living bacteria are virulent.
4. C) the mice survive for a period of a few weeks and then die from an unrelated illness.
5. D) half the mice are killed and the other half survive.
6. E) the mice are killed because the nonvirulent bacteria are transformed into virulent bacteria.

1. What is the central dogma?
2. A) DNA is transcribed into RNA, which is translated into protein.
3. B) RNA is transcribed into DNA, which is translated into protein.
4. C) DNA is transcribed into protein, which is translated into RNA.
5. D) RNA is transcribed into protein, which is translated into DNA.

1. What is the order of processes that support the central dogma?
2. A) DNA replication, translation, protein synthesis
3. B) DNA replication, transcription, translation
4. C) Transcription, DNA replication, translation
5. D) DNA replication, translation, transcription

1. Deoxyribonucleic acid is used for: (Select all that apply.)
2. A) transmission of information.
3. B) storage of information.
4. C) biological catalysis.
5. D) energy storage.
6. E) cell-to-cell communication.

1. A single unit of heredity that contains the information for an individual protein is referred to as a(n) _____.

1. The central dogma of molecular biology states that information flows from:
2. A) DNA directly to protein.
3. B) protein to RNA to DNA.
4. C) DNA to RNA to protein.
5. D) RNA to protein to DNA.
6. E) RNA to DNA to protein.

1. Translation is the process by which:
2. A) the information in DNA is used to synthesize an exact copy of that DNA.
3. B) ribosomes synthesize protein from information in an RNA molecule.
4. C) a section of DNA is used as information to generate an RNA molecule.
5. D) an RNA molecule is used to repair damage to a related DNA molecule.
6. E) ribosomes read the information in a DNA molecule and use it to synthesize protein.

1. Many mutations are detrimental to organisms that acquire them, but other mutations are beneficial and allow evolution of that species.
2. A) True
3. B) False

1. The flow of information from DNA to RNA to protein is referred to as the _____ of molecular biology.

1. Muscle cells make different proteins than nerve cells because they have different sequences of DNA.
2. A) True
3. B) False

1. Why did scientists many years ago believe that protein was the storage molecule for genetic information instead of DNA?
2. A) There are more building blocks for protein than there are for DNA.
3. B) Proteins have a wider variety of three-dimensional shapes than DNA.
4. C) Proteins carry out a great range of cellular functions.
5. D) All of these choices are correct.

1. In the experiments conducted by Avery, McCarty, and MacLeod, which one of the following hypothetical results would indicate that protein, not nucleic acid, was Griffith’s transforming principle?
2. A) None of the extracts from heat-killed cells is able to transform nonvirulent bacteria.
3. B) All of the extracts from heat-killed cells are able to transform nonvirulent bacteria.
4. C) Only the extracts from heat-killed cells treated with RNase are unable to transform nonvirulent bacteria.
5. D) Only the extracts from heat-killed cells treated with DNase are unable to transform nonvirulent bacteria.
6. E) Only the extracts from heat-killed cells treated with protease are unable to transform nonvirulent bacteria.

1. Which of the following statements is TRUE regarding Frederick Griffith’s experiments?
2. A) He demonstrated that proteins serve as the genetic/hereditary material.
3. B) He demonstrated that DNA serves as the genetic/hereditary material.
4. C) He demonstrated that (only) dead virulent bacteria cause pneumonia in mice.
5. D) His experiments relied on RNase and DNase to identify the genetic/hereditary material.
6. E) None of the other answer options is correct.

1. In prokaryotes, newly synthesized proteins are found in the _____ and DNA are observed in the _____.
2. A) cytoplasm; nucleus
3. B) nucleus; cytoplasm
4. C) nucleus; nucleus also
5. D) cytoplasm; cytoplasm also
6. E) nucleus; nucleus also and the cytoplasm

1. In eukaryotes, newly synthesized proteins encoded in genes in the nucleus are found in the _____ and DNA are observed in the _____.
2. A) cytoplasm; nucleus
3. B) nucleus; cytoplasm
4. C) nucleus; nucleus also
5. D) cytoplasm; cytoplasm also
6. E) nucleus; nucleus also or the cytoplasm

1. No exceptions to the central dogma exist. RNA is always transcribed from DNA, and RNA is translated to produce proteins.
2. A) True
3. B) False

1. If protease treatment in Avery, MacLeod, and McCarty’s experiment prevented the transformation of bacteria, what would have been the conclusion of these researchers?
2. A) RNA is the genetic/hereditary material.
3. B) DNA is the genetic/hereditary material.
4. C) Protein is the genetic/hereditary material.
5. D) Protein and RNA are the genetic/hereditary materials.
6. E) Protein and DNA are the genetic/hereditary materials.

1. Imagine that you traveled back in time to the early 1940s. You meet a group of scientists, and tell them that DNA is the hereditary material. Why might the scientists refute your statement?
2. A) DNA is linear and appears relatively “simple.”
3. B) DNA does not appear to (directly) carry out many cellular functions.
4. C) Proteins can have intricate three-dimensional structures.
5. D) Proteins are integral parts of many cellular processes.
6. E) All of these choices are correct.

1. In order to evaluate gene expression, a researcher needs to determine if a protein is produced from her gene of interest.
2. A) True
3. B) False

1. Consider Griffith’s experiment: If he observed healthy mice after injecting these animals with dead virulent and live nonvirulent bacteria, what could he have concluded?
2. A) Genetic information cannot be transferred between mice.
3. B) Genetic information cannot be transferred between bacteria.
4. C) Genetic information is transferrable.
5. D) The RNA of the bacteria used in this experiment was degraded.
6. E) None of the other answer options is correct.

1. When DNA or genetic information is passed between bacteria (and bacteria take up this material from their surrounding environment), this process is referred to as:
2. A)
3. B)
4. C)
5. D)
6. E)

1. Which of the following CORRECTLY describes the complementary base pairing of adenine in both DNA and RNA?
2. A) Adenine pairs with thymine in both DNA and RNA.
3. B) Adenine pairs with uracil in DNA and with thymine in RNA.
4. C) Adenine pairs with thymine in DNA and with uracil in RNA.
5. D) Adenine pairs with cytosine in DNA and with guanine in RNA.
6. E) Adenine pairs with guanine in DNA and with cytosine in RNA.

1. Give the CORRECT complementary base pairs found in DNA and in RNA molecules.

1. Imagine you have discovered a new species of bacteria. To begin your investigation of this organism, you run an assay on the total nucleotide content of the bacterial DNA. If the cytosine content of DNA from the bacterial cells is 40%, what is the adenine content?
2. A) 10 %
3. B) 20%
4. C) 40%
5. D) 605
6. E) It is not possible to calculate this number for prokaryotes.

1. Imagine you have discovered a new species of bacteria. To begin your investigation of this organism, you run an assay on the total nucleotide content of the bacterial cells. If 40 percent of the nucleotides in the DNA are cytosine, what percentage of the DNA is made of adenine nucleotides?

1. DNA is often described as having a shape like a spiral staircase. Which of the spiral staircases in the photos below is the better analogous representation of a DNA molecule?

1. A) A
2. B) B

1. In the spiral staircase analogy of DNA structure, each railing represents a _____ and each step represents a _____.
2. A) sugar-phosphate backbone; pair of bases
3. B) sugar-phosphate backbone; base
4. C) base; the sugar-phosphate backbone of the DNA molecule

1. DNA is often described as having a shape like a spiral staircase. What parts of the DNA molecule are represented by the railings and by the steps?

1. Which of the following is TRUE of DNA?
2. A) Successive nucleotides in a strand are connected by hydrogen bonds.
3. B) A phosphate group in a nucleotide is attached to the 3 carbon in ribose.
4. C) A purine always forms a complementary base pair with a pyrimidine.
5. D) The percentage of the purine A always equals the percentage of the purine G.
6. E) It is used by ribosomes for translation.

1. The complementary base pairing of nucleotides in a DNA molecule is a structural feature that has important implications for DNA’s function. What is the structural relationship between purine and pyrimidine nucleotides?

1. A double-stranded DNA molecule contains 4% of the dinucleotide 5′ –AG–3′. What other dinucleotide also has an abundance of 4%?

1. A double-stranded DNA molecule contains 2% of the trinucleotide 5′ –ATG–3′. What other trinucleotide also has an abundance of 2%?

1. The central dogma of molecular biology refers to:
2. A) replication only.
3. B) transcription only.
4. C) translation only.
5. D) replication and transcription.
6. E) transcription and translation.

1. In a double-stranded DNA molecule, the strands are said to be antiparallel because:
2. A) they wind around one another.
3. B) each purine of one strand pairs with a pyrimidine of another.
4. C) they form an uneven pair of grooves on the outside of molecule.
5. D) one strand runs 5′ to 3′ and the other 3′ to 5′.

1. DNA is isolated from a virus and found to contain 27% A, 27% T, 23% C and 23% G. The DNA is likely to be:
2. A) contaminated with RNA.
3. B)
4. C) single stranded.
5. D) double stranded.

1. In double-stranded DNA, the amount of A equals that of T and the amount of C equals that of G because:
2. A) the strands wind around one another.
3. B) the strands have complementary sequences of bases.
4. C) pyrimidines always pair with each other, as do purines.
5. D) one strand runs 5′ to 3′ and the other 3′ to 5′.

1. In a DNA strand, successive nucleotides are linked by:
2. A) hydrogen bonds
3. B) base stacking
4. C) 3′-5′ phosphodiester bonds
5. D) 2′-5′ phosphodiester bonds
6. E) peptide bonds

1. Chromatin is composed of:
2. A) histones and DNA.
3. B) histones, DNA and RNA.
4. C) histones, DNA, and acidic proteins.
5. D) histones and DNA surrounded by a membrane.

1. In double-stranded DNA, the sugar-phosphate backbones are:
2. A) on the outside, separated by grooves of equal size.
3. B) on the outside, separated by grooves of unequal size.
4. C) on the inside, separated by grooves of equal size.
5. D) on the inside, separated by grooves of unequal size.

1. Which one of the following nucleotides hydrogen base pairs with adenine in an RNA molecule?
2. A) cytosine
3. B) thymine
4. C) uracil
5. D) adenine
6. E) guanine

1. If the first nucleotide after the promoter on the top DNA strand is changed from G to T, what would the resulting nucleotide be on the mRNA?
2. A) A
3. B) C
4. C) T
5. D) G

1. If the first nucleotide after the promoter on the bottom DNA strand in the simulation is changed from C to T, what would the resulting nucleotide be on the mRNA? Test your prediction by making the change and running the simulation.
2. A) A
3. B) C
4. C) T
5. D) U

1. Occasionally, a double-stranded DNA molecule contains a uracil base (U) instead of T. If a U were present in the template strand of DNA, what base do you think would be incorporated into the RNA transcript at that position?
2. A) U
3. B) C
4. C) T
5. D) A
6. E) G

1. Which one of the following statements about RNA is INCORRECT?
2. A) The nucleotide at the 5′ end of an RNA molecule is typically a nucleoside triphosphate.
3. B) RNA is usually found in double-stranded form, just like DNA.
4. C) RNA molecules are typically shorter than DNA molecules.
5. D) RNA molecules can form base pairs within a single strand.
6. E) RNA molecules are capable of evolving their enzymatic activity over time.

1. Which one of the following is LEAST likely to be found in a nucleotide?
2. A) one or more phosphate groups
3. B) a five-carbon sugar
4. C) a side chain
5. D) a nitrogen-containing base
6. E) All of the choices are equally likely to be found in a nucleotide.

1. In a nucleotide, the phosphate is attached to the _____ carbon of the sugar, and the base is attached to the _____ carbon of the sugar.
2. A) 1′; 5′
3. B) 2′; 3′
4. C) 3′; 5′
5. D) 5′; 1′
6. E) 5′; 3′

1. A five-carbon sugar connected to a purine or pyrimidine ring is MOST accurately referred to as a(n) _____.

1. Which of the following statements about DNA is/are CORRECT? (Select all that apply.)
2. A) DNA typically exists in cells as a double helix.
3. B) There are 10 base pairs per turn in a helical DNA molecule.
4. C) Adenine is complementary to cytosine.
5. D) The strands in DNA wrap around each other in a helix that coils to the right.
6. E) Successive nucleotides are attached by peptide bonds.

1. Which one of the following represents an actual Watson-Crick base pair with the LARGEST number of hydrogen bonds?
2. A) adenine and cytosine
3. B) cytosine and guanine
4. C) thymine and guanine
5. D) cytosine and thymine
6. E) adenine and thymine

1. Which one of the following activities would LEAST likely be found in a topoisomerase?
2. A) cutting a phosphodiester linkage
3. B) inducing or relaxing twists in double-stranded DNA
4. C) adding nucleotides to the end of a DNA strand
5. D) reforming phosphodiester linkages
6. E) Topoisomerases are equally likely to perform all of these functions.

1. Which type of protein does DNA wrap around so that it can be packaged in a cell?
2. A) histones
3. B) topoisomerase
4. C) ribosomal proteins
5. D) DNA polymerase
6. E) spliceosome proteins

1. Why aren’t nucleosides incorporated into DNA?
2. A) The bases are not fully assembled.
3. B) The sugar is not in the right form.
4. C) There are no phosphates to make the phosphodiester bonds.
5. D) The peptide bonds don’t form.

1. Sometimes the sequence of DNA gets mutated and an adenine is paired to a cytosine. Why is this interaction unstable?
2. A) Because the phosphate groups of the two bases repel each other.
3. B) Because an ionic bond cannot be formed between the two.
4. C) Because the chemical groups that form hydrogen bonds are in the wrong positions.
5. D) Because the charges on the bases repel one another.

1. In the DNA of certain bacterial cells, 16% of the nucleotides are adenine. What are the percentages of the other nucleotides in the bacterial DNA?
2. A) 16% thymidine, 34% guanine, 34% cytosine
3. B) 34% uracil, 16% guanine, 16% cytosine
4. C) 34% thymidine, 34% guanine, 16% cytosine
5. D) 34% thymidine, 16% guanine, 34% cytosine

1. In the DNA of certain bacterial cells, 16% of the nucleotides are adenine. What are the percentages of the other nucleotides in the bacterial DNA?

1. Imagine that you are an interior architecture/biology double major. While at home during break, one of your friends asks you to design and help build a spiral staircase that is modeled after a DNA molecule. The staircase must have 12 steps, and each step needs to be 6 feet wide. You say, “OK, as long as you provide the materials.” So, your friend asks you for a list of materials needed to build the staircase. Which of the following includes the items necessary to make a staircase that is based on the molecular structure of a DNA molecule?
2. A) 1 railing and 12 boards (each of which is 6 feet wide)
3. B) 2 railings and 12 boards (each of which is 6 feet wide)
4. C) 2 railings and 24 boards (12 that are 2 feet long and 12 that are 4 feet long)
5. D) 2 railings and 24 boards (each of which is 3 feet long)
6. E) 1 railing and 24 boards (12 that are 2 feet long and 12 that are 4 feet long)
7. F) 1 railing and 24 boards (each of which is 3 feet long)

1. Imagine that you are an interior architecture/biology double major. While at home during break, one of your friends asks you to design and help build a spiral staircase that is modeled after a DNA molecule. The staircase must have 12 steps and each step needs to be 6 feet wide. You say, “OK, as long as you provide the materials.” Then your friend shows you what you have to work with: a couple of spiral railings and some boards. The trouble is the only boards he has for you to work with are either 2 feet long or 4 feet long. Explain why you are still able to design and build the staircase using the materials he has on hand.

1. In the DNA sequence 5’–TGAC–3′, the phosphodiester linkage between the guanine and the adenine connects:
2. A) the 3′ end of the guanine to the 5′ end of the adenine.
3. B) the 2′ end of the adenine to the 3′ end of the guanine.
4. C) the 5′ end of the guanine to the 1′ end of the adenine.
5. D) the 3′ end of the adenine to the 5′ end of the guanine.
6. E) the 5′ end of the guanine to the 2′ end of the adenine.

1. The strands in a DNA molecule are: (Select all that apply.)
2. A)
3. B)
4. C)
5. D)
6. E) covalently bonded to each other.

1. If a DNA molecule is visualized as a wood screw from a hardware store, the threads in the screw would be spaced identical distances from each other.
2. A) True
3. B) False

1. The hydrophobicity of the planar nitrogenous ring structures of a nucleotide, leading to the exclusion of water and stability of DNA, is referred to as:
2. A) Watson-Crick base pairing.
3. B)
4. C) base-stacking interactions.
5. D)
6. E)

1. An organism’s genomic DNA is analyzed and found to contain 22% thymine. What percentage of that organism’s DNA is guanine?
2. A) 22%
3. B) 28%
4. C) 44%
5. D) 56%
6. E) 78%

1. The covalent linkage between nucleotides is referred to as a(n) _____ bond.

1. DNA wraps around histone and other proteins to form _____.

1. Supercoils in DNA are induced or relaxed by enzymes called topoisomerases.
2. A) True
3. B) False

1. Which one of the following represents a standard Watson-Crick base pair interaction?
2. A) G-T
3. B) C-A
4. C) G-C
5. D) A-G
6. E) T-C

1. In the sequence AGGCCT, an available phosphate group would be found at the 5′ end of the nucleotide labeled “T.”
2. A) True
3. B) False

1. Which of the following is NOT a component of a nucleotide?
2. A) a five-carbon sugar
3. B) one or more phosphate groups
4. C) a nitrogen-containing base
5. D) a carboxyl group
6. E) All of these choices are correct.

1. In a deoxyribonucleotide, what chemical group is found at the 2′ carbon of the sugar component?
2. A) an oxygen
3. B) a hydroxyl group
4. C) one or more phosphate groups
5. D) an amino group
6. E) a hydrogen

1. In a nucleotide, to which carbon in the sugar is the base attached?
2. A) 1′
3. B) 2′
4. C) 3′
5. D) 4′
6. E) 5′

1. Nucleic acid or protein sequences that are very similar from one organism to another are called:
2. A)
3. B)
4. C)
5. D) coding sequences.

1. Select the answer option that arranges the following in order from smallest to largest.
2. A) genome, gene, nucleotide, nucleoside
3. B) gene, nucleotide, genome, nucleoside
4. C) nucleoside, nucleotide, gene, genome
5. D) nucleotide, nucleoside, gene, genome
6. E) nucleoside, nucleotide, genome, gene

1. The strands in a double helix of DNA are:
2. A)
3. B)
4. C) held together via hydrogen bonds.
5. D) wound around each other with 10 base pairs per turn.
6. E) All of these choices are correct.

1. Which of the following forces contribute to the stability of a DNA double helix?
2. A) hydrophobic interactions of bases in the same strand
3. B) hydrogen bonding between bases in opposite strands
4. C) ionic interactions between the positively charged component of one base and the negatively charged component of the neighboring base
5. D) hydrophobic interactions of bases in the same strand and hydrogen bonding between bases in opposite strands
6. E) hydrophobic interactions of bases in the same strand, hydrogen bonding between bases in opposite strands, and ionic interactions between the positively charged component of one base and the negatively charged component of the neighboring base

1. An organism’s genome is analyzed and found to contain 18% thymine. What percentage of that organism’s DNA is cytosine?
2. A) 32%
3. B) 18%
4. C) 82%
5. D) 64%
6. E) 36%

1. A deoxyribose linked to a thymine is referred to as a:
2. A)
3. B)
4. C) purine nucleotide.
5. D) purine nucleoside.
6. E) nucleotide or purine nucleotide.

1. Scientists can determine the size of DNA fragments through a process known as gel electrophoresis. In this process, DNA is loaded into a gel submerged in a liquid solution through which an electric current is run. Large DNA molecules move slower and can be observed at the top of the gel, whereas smaller DNA fragments move faster and are seen at the bottom of the gel. Based on what you know about the properties of DNA, how is the electric current arranged in this process?
2. A) Since DNA is negatively charged, the negative end is placed at the top of the gel, and the positive end is placed at the bottom of the gel.
3. B) Since DNA is negatively charged, the positive end is placed at the top of the gel, and the negative end is placed at the bottom of the gel.
4. C) Since DNA is positively charged, the negative end is placed at the top of the gel, and the positive end is placed at the bottom of the gel.
5. D) Since DNA is positively charged, the positive end is placed at the top of the gel, and the negative end is placed at the bottom of the gel.
6. E) Since DNA is uncharged, the placement of the positive end and negative end does not matter.

1. Which one of the following CORRECTLY lists the components necessary for eukaryotic transcription?
2. A) RNA polymerase, general transcription factors, DNA, and RNA nucleotides
3. B) RNA polymerase, general transcription factors, DNA, and DNA nucleotides
4. C) ribosomes, general transcription factors, DNA, and DNA nucleotides
5. D) ribosomes, general transcription factors, DNA, and RNA nucleotides

1. List the components required for eukaryotic transcription.

1. RNA makes up the genome of many different viruses, and it was probably the first information molecule in evolutionary history. Yet, cells use DNA as the primary molecule for the storage of genetic information. What features of DNA make it a more suitable informational archive than RNA? (Select all that apply.)
2. A) The –H group on the 2 carbon of deoxyribose is less reactive than the –OH on the same carbon of ribose.
3. B) Only DNA is capable of binding to proteins.
4. C) Double-stranded DNA facilitates rapid and accurate replication of the information.
5. D) DNA has stronger phosphodiester bonds than RNA does.
6. E) DNA is converted to RNA by a spontaneous hydrolysis reaction.

1. What features of DNA make it a more suitable informational archive than RNA?

1. A protein-coding primary transcript contains 3 exons that may be alternatively spliced in such a way that the processed messenger RNA may contain any 1, any 2, or all 3 exons. How many alternatively processed transcripts are possible?

1. Protein-coding primary transcript exons may be alternatively spliced in such a way that the processed messenger RNA may contain any 1, any 2, any 3, etc., exons, including the possibility of all of them, How many exons would be needed in the primary transcript to allow a total of 31 alternatively spliced forms?

1. RNA polymerase complex can do which of the following?
2. A) allow RNA-DNA hybrids to form
3. B) release a finished RNA transcript from a DNA template
4. C) separate DNA strands
5. D) restore the original DNA strands
6. E) All of these choices are correct.

1. In which of the following cellular processes is RNA involved?
2. A) transcription
3. B) translation
4. C) splicing
5. D) transcription and translation
6. E) All of these choices are correct.

1. In an RNA world, which of the following processes would NOT take place?
2. A) transcription
3. B) translation
4. C) DNA replication
5. D) None of the other answer options is correct.

1. Transcription is sometimes described as a process in which RNA is “copied” from the template strand of DNA. This statement is potentially misleading because:
2. A) RNA nucleotides contain ribose and so cannot be an exact copy of DNA.
3. B) the RNA transcript and the DNA template strand are antiparallel.
4. C) the RNA transcript has a complementary sequence of bases to the template strand.
5. D) RNA molecules contain uracil instead of thymine
6. E) All of these choices are correct.

1. A template DNA strand contains the sequence 5′-ATGCTGAC-3′. The corresponding sequence in the RNA transcript is:
2. A) 5′-TACGACTG-3′.
3. B) 5′-GTCAGCAT-3′.
4. C) 5′-UACGACUG-3′.
5. D) 5′-GUCAGCAU-3′.

1. A template DNA strand contains the sequence 3′-ATGCTGAC-5′. The corresponding sequence in the RNA transcript is:
2. A) 5′-TACGACTG-3′.
3. B) 5′-GTCAGCAT-3′.
4. C) 5′-UACGACUG-3′.
5. D) 5′-GUCAGCAU-3′.

1. A template DNA strand contains the sequence 3′-ATGCTGAC-5′. This strand is transcribed:
2. A) from left to right.
3. B) from right to left.

1. In the process of transcription, the RNA transcript is synthesized:
2. A) from the 3′ end to the 5′ end.
3. B) from the 5′ end to the 3′ end.

1. A template DNA strand contains 30% A, 20%T, 27% G, and 23% C. The RNA transcript contains:
2. A) 30% A, 20% T, 27% G, and 23% C.
3. B) 30% T, 20% A, 27% C, and 23% G.
4. C) 30% U, 20% A, 27% C, and 23% G.
5. D) 30% A, 20% U, 27% G, and 23% C.

1. Transcription of RNA from DNA in eukaryotes requires:
2. A) transcription factors.
3. B) activator proteins.
4. C) a promoter sequence.
5. D) RNA polymerase.
6. E) All of these choices are correct.

1. In transcription, each added ribonucleotide comes into the RNA polymerase complex as a:
2. A)
3. B) nucleoside monophosphate.
4. C) nucleoside diphosphate.
5. D) nucleoside triphosphate.

1. In transcription, the energy to attach each successive ribonucleotide to the growing RNA chain comes from:
2. A) the RNA polymerase itself.
3. B) cleavage of the high-energy phosphate bonds of the incoming nucleotide.
4. C) cleavage of the high-energy phosphate bonds of the growing transcript.
5. D) cleavage of the 2′ hydroxyl group on the ribose of the incoming nucleotide.

1. What steps are necessary for eukaryotic transcription to begin? (Select all that apply.)
2. A) Transcriptional activator proteins bind to enhancers.
3. B) General transcription factors bind to the promoter.
4. C) General transcription factors and sigma factor bind to the promoter.
5. D) DNA looping brings transcriptional activator proteins, general transcription factors, sigma factor and RNA Pol II together.
6. E) DNA looping brings transcriptional activator proteins, general transcription factors, mediator complex and RNA Pol II together.

1. What is the name of the enzyme complex that forms at the start of transcription?
2. A) DNA polymerase
3. B) RNA polymerase
4. C) DNA gyrase
5. D) RNA helicase

1. Which of the following molecules is made during the process of transcription?
2. A) mRNA
3. B) tRNA
4. C) rRNA
5. D) All of these choices are correct.

1. If you made a change in the promoter sequence in the DNA that inactivates the promoter, what would happen at the RNA level?
2. A) Nothing, the RNA would be made as usual.
3. B) The mutation of the DNA would be carried through to the RNA sequence.
4. C) The RNA polymerase would not be able to recognize and bind the DNA, so no RNA would be made.
5. D) The DNA helicase would not be able to recognize and bind the DNA, so the RNA would not be made.

1. Whichever DNA strand is transcribed, the RNA polymerase reads the template strand from 3 to 5.
2. A) True
3. B) False

1. In an RNA world:
2. A) RNA functions for information storage and proteins do catalysis.
3. B) DNA functions for information storage and RNA does catalysis.
4. C) RNA functions for information storage and for catalysis.
5. D) RNA functions for information storage and there is no catalysis.
6. E) None of the other answer options is correct.

1. Which of the following is essential, even in an RNA world?
2. A) polymerase
3. B) transcription
4. C) translation
5. D) spliceosomes
6. E) transfer RNA

1. RNA catalysis can be selected in laboratory experiments.
2. A) True
3. B) False

1. RNA catalysis means that RNA can:
2. A) function as an information-storage molecule.
3. B) function as a signaling molecule.
4. C) form membrane-like structures.
5. D) function like an enzyme.

1. In E. coli the molecule(s) responsible for promoter recognition is/are referred to as:
2. A) the sigma factor.
3. B) the TATA box.
4. C) the mediator complex.
5. D) an enhancer.
6. E) transcription factors.

1. In eukaryotes, activator proteins bind to _____; generalized transcription factors bind to _____.
2. A) promoters; terminators
3. B) DNA polymerases; RNA polymerases
4. C) promoters; enhancers
5. D) terminators; RNA polymerases
6. E) enhancers; promoters

1. In eukaryotes, where do general transcription initiation factors bind?
2. A) 5′ UTR
3. B) promoter
4. C) donor splice site
5. D) near the start codon
6. E) 5′ cap

1. During transcription of a given protein-coding gene, both strands are used as template.
2. A) True
3. B) False

1. In a long double-stranded DNA molecule containing the genetic information for many genes, the template strand for one gene may be the nontemplate strand for another gene along the way.
2. A) True
3. B) False

1. Which of the following numbers is closest to the number of bases of RNA that at any one time are hydrogen bonded to DNA within an RNA polymerase in E. coli?
2. A) 1
3. B) 10
4. C) 100
5. D) 1000
6. E) 10,000

1. Where does the energy come from to add a uracil to the 3′ end of a transcript?
2. A) the energy released by allowing the uracil to complementary base pair with an adjacent thymine
3. B) the hydrolysis of a terminal phosphate from the incoming UTP molecule
4. C) the cell’s supply of ATP
5. D) the hydrolysis of pyrophosphate from the incoming UTP molecule
6. E) the hydrolysis of all three phosphate groups from the incoming UTP molecule

1. Which one of the following statements about RNA is CORRECT?
2. A) RNA is a more stable molecule than DNA.
3. B) RNA has the same 5-carbon sugars as DNA.
4. C) RNA uses the same pyrimidine bases as DNA.
5. D) RNA uses the same purine bases as DNA.
6. E) All of these choices are correct.

1. What would happen if an enhancer sequence were mutated so that its binding partner was always bound and recruiting the RNA polymerase complex?
2. A) No transcription would occur as the site is now blocked to other proteins.
3. B) Transcription wouldn’t change.
4. C) No transcription would occur because the mediator complex could not form.
5. D) Transcription would occur continuously.

1. A template strand of DNA is read in the _____ direction in order to direct synthesis of RNA in the _____ direction.
2. A) 3’–5′; 3’–5′
3. B) 5’–3′; 3’–5′
4. C) 3’–5′; 5’–3′
5. D) 5’–3′; 5’–3′

1. Transcription continues until:
2. A) all bases in the DNA are copied.
3. B) a stop codon is encountered.
4. C) a terminator sequence is encountered.
5. D) a ribosome pulls RNA polymerase off the DNA.
6. E) a transcription factor signals the end of the gene.

1. Based on what you know about eukaryotic cells, what is one of the arguments against using RNA as the genetic storage molecule?
2. A) Because RNA uses uracil instead of thymine, it cannot hold genetic information.
3. B) RNA has a negatively charged sugar phosphate backbone.
4. C) The structure of RNA does not allow for double-stranded base pairing.
5. D) There is no current mechanism to package enough RNA to encode all the information needed by the cell.
6. E) The secondary structure of RNA prevents its replication before cell division.

1. Based on what you know about eukaryotic cells, what is one of the arguments against using RNA as the genetic storage molecule?

1. The idea that, when life originated on Earth, a macromolecule other than DNA served the role of information storage and that this same macromolecule carried out catalysis is called the _____ hypothesis.
2. A) water world
3. B) carbon world
4. C) macromolecular world
5. D) RNA world

1. The experiment of replicating RNA, introducing random mutations, and repeating the process on a small subset of products able to carry out a specific chemical reaction mimics the process of:
2. A) DNA replication.
3. B)
4. C)
5. D) natural selection.

1. Ribose differs from deoxyribose in that a ribose:
2. A) has an extra hydroxyl group.
3. B) is missing a hydroxyl group.
4. C) has an extra phosphate group.
5. D) is missing a phosphate group.

1. The base uracil pairs with:
2. A)
3. B)
4. C)
5. D)

1. Some RNA molecules possess catalytic activity.
2. A) True
3. B) False

1. The type of RNA that physically interacts with a ribosome, providing the sequence information for a specific protein, is abbreviated:
2. A)
3. B)
4. C)
5. D)
6. E)

1. In an RNA world:
2. A) RNA functions in information storage and proteins do catalysis.
3. B) DNA functions in information storage and RNA alone catalyzes reactions.
4. C) RNA functions in information storage and for catalysis.
5. D) RNA functions in information storage and there is no catalysis.
6. E) None of the other answer options is correct.

1. RNA catalysis can be selected in laboratory experiments.
2. A) True
3. B) False

1. The production of an RNA molecule using DNA as a template is referred to as _____.

1. An RNA transcript is synthesized in which direction?
2. A) N terminus to C terminus
3. B) C terminus to N terminus
4. C) 5′ to 3′
5. D) 5′ to 5′
6. E) 3′ to 5′

1. The same strand in a DNA double helix is used as the template strand for transcription of every gene in a given chromosome.
2. A) True
3. B) False

1. In order for a nucleotide to be added to a growing RNA strand, the polymerase ensures that hydrogen bonds between the incoming base and the template strand are properly made before the high-energy phosphate bond is cleaved.
2. A) True
3. B) False

1. In a bacterial transcription complex, how many base pairs of RNA-DNA hybrid are found?
2. A) 2
3. B) 8
4. C) 25
5. D) 35
6. E) 100

1. Transcription starts at a _____ and ends at a _____.
2. A) promoter; terminator
3. B) 5′ cap; terminator
4. C) promoter; 5′ end
5. D) 3′ end; 5′ end

1. Transcriptional activator proteins bind to a specific DNA sequence referred to as a(n) _____.

1. A polymerization reaction is made irreversible by:
2. A) hybridization of a free nucleotide to a template.
3. B) breaking of the bond between the 2′ carbon and the hydroxyl group.
4. C) creation of a phosphodiester bond.
5. D) hydrolysis of a pyrophosphate group into two inorganic phosphates.
6. E) the entry of a free nucleotide into an RNA polymerase.

1. Which one of the following is NOT a way in which RNA differs from DNA?
2. A) RNA has uracil as one of its bases and DNA has thymine.
3. B) RNAs are typically single-stranded and DNA is double-stranded.
4. C) RNA nucleotides can have only a single phosphate group and DNA nucleotides have one, two, or three phosphate groups.
5. D) RNA molecules are usually much shorter than DNA molecules.
6. E) The sugar component of RNA nucleotides is ribose and the sugar component of DNA nucleotides is deoxyribose.

1. A transcribed region of DNA has a 5′ to 3′ sequence TTCATGGCGAC. The 5′ to 3′ sequence of an RNA transcribed from this DNA would be 5′-_____-3′.

1. Many promoters of a hypothetical conserved gene have mostly adenines and thymines. What is the MOST likely reason for this high proportion of adenines and thymines?
2. A) RNA polymerases are better at incorporating uracils and thymines into RNA molecules than incorporating guanines and cytosines.
3. B) This is the region for separating template and nontemplate strands, and A-T base pairs are easier to separate than G-C base pairs.
4. C) Accessory proteins like sigma factors or transcription factors bind more easily to AT-rich sequences than they do to GC-rich sequences.
5. D) It is possible to create more unique sequences for recognition with adenines and thymines than it is with guanines and cytosines.
6. E) None of the other answer options is correct.

1. Mutations only occur in DNA, and never are observed in RNA.
2. A) True
3. B) False

1. Which of the following statements about RNA is FALSE?
2. A) RNA is not as stable as DNA.
3. B) RNA contains uracil.
4. C) RNA is typically single-stranded.
5. D) RNA can be produced via transcription.
6. E) RNA contains equal proportions of G and C nucleotides.

1. When RNA is transcribed, the RNA/DNA complex extends for the entire length of the DNA sequence of interest.
2. A) True
3. B) False

1. An intron is:
2. A) a polypeptide that is clipped out of a larger protein post-translationally.
3. B) an RNA sequence that is removed during the processing of an RNA molecule in the nucleus.
4. C) part of an intact, mature mRNA that leaves the nucleus.
5. D) part of an RNA transcript that is not present in the DNA template.
6. E) a type of transfer RNA.

1. An exon is:
2. A) a protein that is clipped out post-translationally.
3. B) RNA that is removed during the processing of an RNA molecule and remains inside the nucleus.
4. C) part of an intact, mature mRNA that leaves the nucleus.
5. D) a transfer RNA that binds to the codon.
6. E) a series of amino acids at the end of a new polypeptide that directs transcription to the ER.

1. What is an intron?

1. What is an exon?

1. In order to test the effects of a new drug, you isolate the messenger RNA molecules from both treated and untreated eukaryotic cells and separate them according to size using gel electrophoresis. In each lane of the gel, the shorter RNA molecules migrate more quickly through the gel and end up near the bottom of the gel while the longer RNAs migrate more slowly and remain near the top.

The samples that were loaded into each of the four lanes are as follows:

Lane 1: the primary RNA transcripts isolated from the nucleus of untreated cells

Lane 2: the primary RNA transcripts isolated from the nucleus of cells treated with the drug being tested

Lane 3: RNA isolated from the cytosol of untreated cells

Lane 4: RNA isolated from the cytosol of cells treated with the drug being tested

Which of the following conclusions is most likely to be CORRECT?

1. A) These results suggest that the drug inhibits post-translational processing of this gene.
2. B) These results suggest that the drug contains a protease that targets this gene product.
3. C) These results suggest that the drug digests DNA.
4. D) These results suggest that the drug affects RNA processing.
5. E) These results suggest that the drug inhibits DNA replication.

1. In order to test the effects of a new drug, you isolate the messenger RNA molecules from both treated and untreated eukaryotic cells and separate them according to size using gel electrophoresis. In each lane of the gel, the shorter RNA molecules migrate more quickly through the gel and end up near the bottom of the gel while the longer RNAs migrate more slowly and remain near the top.

The samples that were loaded into each of the four lanes are as follows:

Lane 1: the primary RNA transcripts isolated from the nucleus of untreated cells

Lane 2: the primary RNA transcripts isolated from the nucleus of cells treated with the drug being tested

Lane 3: RNA isolated from the cytosol of untreated cells

Lane 4: RNA isolated from the cytosol of cells treated with the drug being tested

Based on the information provided by the gel shown above, what cellular process appears to be affected by the new drug?

1. List two features of polycistronic mRNAs.

1.	Which property of membrane phospholipids allows membrane proteins involved in the same biochemical pathway to associate with each other?

2.	Purified phospholipids gather together and form membranes only if the appropriate enzyme is present.
	A)	True
	B)	False

3.	Which component of a phospholipid is found in the interior of a lipid bilayer?
	A)	glycerol
	B)	fatty acids
	C)	phosphate group

4.	Phospholipids spontaneously form a variety of structures in aqueous solution. This property accounts at least in part for which of the following?
	A)	the first cells
	B)	formation of lipid bilayers
	C)	the ability of vesicles to fuse with the plasma membrane (exocytosis)
	D)	the ability of vesicles to bud off from the plasma membrane (endocytosis)
	E)	All of the answer options depend on this property of phospholipids.

5.	The lipid components of cellular membranes often include:
	A)	phospholipids.
	B)	phospholipids and fatty acids.
	C)	fatty acids and cholesterol.
	D)	phospholipids and cholesterol.

6.	List the lipid components of cellular membranes.

7.	In response to seasonal changes in temperature, many organisms must alter the composition of their plasma membranes to maintain the proper degree of fluidity. As summer turns to fall and eventually into winter, which of the following would you predict you would observe in the plasma membranes of organisms that are unable to regulate their body temperature?
	A)	an increase in phospholipid fatty acid side chain length and an increase in side chain saturation
	B)	a decrease in phospholipid fatty acid side chain length and an increase in side chain saturation
	C)	a decrease in phospholipid fatty acid side chain length and a decrease in side chain saturation
	D)	an increase in phospholipid fatty acid side chain length and a decrease in side chain saturation

8.	In order for bilayers to form spontaneously, the pH of the solution should be:
	A)	very acidic.
	B)	moderately acidic.
	C)	approximately neutral.
	D)	moderately basic.
	E)	very basic.

9.	The first cells were surrounded by a membrane composed largely of lipids synthesized by intracellular proteins.
	A)	True
	B)	False

10.	Paramecium is a unicellular organism that lives in fresh water. Suppose you are studying two populations of this organism: one population lives in a pond in northern Ontario, Canada, and the other lives in a pond in southern Florida. If you examined the plasma membranes of both of these populations at the same time of year, what difference would you expect to find between the two populations’ cell membranes?
	A)	The fatty acid side chains in the membrane phospholipids of the Florida Paramecia would generally be longer and would be more saturated compared to those in the membranes of the Canada Paramecia.
	B)	The fatty acid side chains in the membrane phospholipids of the Florida Paramecia would generally be shorter and would be more saturated compared to those in the membranes of the Canada Paramecia.
	C)	The fatty acid side chains in the membrane phospholipids of the Florida Paramecia would generally be longer and would be less saturated compared to those in the membranes of the Canada Paramecia.
	D)	The fatty acid side chains in the membrane phospholipids of the Florida Paramecia would generally be shorter and would be less saturated compared to those in the membranes of the Canada Paramecia.

11.	Freeze fracture is a technique used to visualize membrane proteins. In this technique, cells are rapidly frozen and then split, separating the lipid bilayer into its two component layers. Transmembrane proteins stay associated with one layer and leave a pit in the other. The fluid mosaic model predicts what kind of pattern of proteins and pits?
	A)	a random arrangement of proteins and pits
	B)	a random arrangement of proteins, but an ordered arrangement of pits
	C)	an ordered arrangement of proteins, but a random arrangement of pits

12.	Molecules that have both hydrophilic and hydrophobic regions are referred to as _____.

13.	Specific types of lipids assemble into defined areas of a biological membrane referred to as:
	A)	sphingopatches.
	B)	lipid rafts.
	C)	biomembrane aggregation regions (BARs).
	D)	plaques.
	E)	cholesterol plugs.

14.	Which one of the following describes the hydrophilic component of cholesterol?
	A)	a hydroxyl group only
	B)	a phosphate group only
	C)	a phosphate group and a chemical group called choline
	D)	a group of four planar rings and a hydroxyl group
	E)	a single hydrocarbon tail

15.	Which one of the following is considered an integral membrane protein?
	A)	a protein with its N-terminus in the cytoplasm and its C-terminus in the extracellular space
	B)	a protein attached to a transmembrane protein via hydrogen bonding
	C)	a protein attached to a phospholipid via ionic bonding with the head group of the lipid molecule
	D)	a protein capable of diffusing throughout the cytoplasm of a cell

16.	Of the major taxonomic groups of organisms mentioned in Chapter 1 (Section 1.3), list those whose cells have a plasma membrane.

17.	Many environmental factors influence the structure of biological membranes. Which one of the following could permanently disrupt phospholipid bilayers in an aqueous solution?
	A)	the addition of acid to change the pH
	B)	physical agitation of the solution
	C)	slight elevation of the temperature

18.	Explain how the basic structure of a phospholipid bilayer is maintained in an aqueous solution, and identify a change you can make that would permanently disrupt the bilayer.

19.	Phospholipase is an enzyme that cleaves the phosphate head group off a phospholipid molecule. The plasma membrane is not, however, permeable to the enzyme. Imagine a cell where phospholipid A is present in the layer of phospholipds facing the exterior of the cell, and phospholipid B is present in the layer of phospholipds facing the interior of the cell. After adding phospholipase to the medium in which the cell is growing, what would you expect to find in the fluid surrounding the cell?
	A)	the phosphate head group from phospholipid A only
	B)	the phosphate head group from phospholipid B only
	C)	phosphate head groups from both phospholipids A and B
	D)	phosphate head groups from neither phospholipids A nor B

20.	Which of the following would be expected to decrease the fluidity of a membrane?
	A)	an increase in phospholipid fatty acid chain length and an increase in chain saturation
	B)	a decrease in phospholipid fatty acid chain length and an increase in chain saturation
	C)	a decrease in phospholipid fatty acid chain length and a decrease in chain saturation
	D)	an increase in phospholipid fatty acid chain length and a decrease in chain saturation

21.	Why does a phospholipid on the cytoplasmic side of the cell membrane rarely flip to the extracellular side if both environments are polar?
	A)	The polar head group cannot pass through the nonpolar interior.
	B)	The two sides have different functions and thus the phospholipid would not function properly.
	C)	The cytoplasmic phospholipid is too big to pass through the membrane.
	D)	The cholesterol does not allow lipids to move.

22.	If FRAP is performed on two membranes, one at 25ºC and the other at 40ºC, which one of the following results would most likely be observed?
	A)	Only the membrane at the higher temperature would recover fluorescence in the bleached area.
	B)	Only the membrane at the lower temperature would recover fluorescence in the bleached area.
	C)	Both membranes would recover fluorescence in the bleached area, but the membrane at the colder temperature would recover more rapidly.
	D)	Both membranes would recover fluorescence in the bleached area, but the membrane at the warmer temperature would recover more rapidly.
	E)	Both membranes would recover fluorescence in the bleached area at the same rate.

23.	A spontaneously generated enclosed bilayer structure is called a(n) _____.

24.	Figure 5.2 shows a common biological phospholipid called phosphatidyl choline. Which of the following is NOT a component of phosphatidyl choline?
	A)	glycerol
	B)	choline
	C)	phosphate
	D)	three fatty acids
	E)	None of the answer options is correct.

25.	Exposure of purified phospholipids to water results in the spontaneous formation of:
	A)	lipid bilayers.
	B)	triacylglycerols.
	C)	steroids.
	D)	polypeptides.
	E)	carbohydrates.

26.	Which one of the following is NOT a component of an animal cell’s plasma membrane?
	A)	protein
	B)	lipid
	C)	nucleic acid
	D)	carbohydrate

27.	Amino acids with hydrophobic side chains are often found in the region of an integral membrane protein that spans the membrane.
	A)	True
	B)	False

28.	Long, saturated fatty acid tails _____ lipid mobility and _____ membrane fluidity.
	A)	enhance; increase
	B)	reduce; increase
	C)	maintain; decrease
	D)	enhance; maintain
	E)	reduce; decrease

29.	Which of the following is a common function of membrane proteins? (Select all that apply.)
	A)	catalysis
	B)	attachment
	C)	transport
	D)	signal reception

30.	What type of molecule is NOT associated with a cell’s plasma membrane?
	A)	carbohydrate
	B)	phospholipid
	C)	RNA
	D)	protein

31.	The interior region of a phospholipid bilayer is characterized as:
	A)	hydrophilic.
	B)	hydrophobic.
	C)	polar.
	D)	hydrophilic and polar.

32.	A phospholipid molecule in a membrane can:
	A)	spin (rotate around its vertical axis).
	B)	move side to side (lateral movement).
	C)	flip (rotate between the two halves of the bilayer).
	D)	both spin (rotate around its vertical axis) and move side to side (lateral movement).

33.	Which part of a cholesterol molecule is polar?
	A)	the OH group
	B)	the four interconnected planar rings
	C)	the hydrocarbon tail
	D)	both the four interconnected planar rings and the hydrocarbon tail

34.	A protein that is temporarily associated with a biological membrane is a(n):
	A)	transmembrane protein.
	B)	integral membrane protein.
	C)	peripheral membrane protein.
	D)	transmembrane protein and an integral membrane protein.

35.	An amphipathic molecule is one that:
	A)	contains both polar and nonpolar regions.
	B)	has a head and tail domain.
	C)	makes up a membrane.
	D)	can fully dissolve in water.

36.	How is a micelle different from a liposome?
	A)	A micelle is composed of a single layer of phospholipids.
	B)	Micelle phospholipids have bulky head groups.
	C)	Micelle phospholipids have a single fatty acid tail.
	D)	All of these choices are correct.

37.	Some lipid rafts are characterized by an accumulation of cholesterol. What does this mean for the fluidity of the raft domain?
	A)	These lipid rafts are more fluid than the surrounding membrane at normal temperatures.
	B)	These lipid rafts are less fluid than the surrounding membrane at normal temperatures.
	C)	These lipid rafts are equally fluid as the surrounding membrane independent of temperature.
	D)	These lipid rafts are less fluid than the surrounding membrane at low temperatures.

38.	Predict how phospholipids arrange themselves when they are placed in a nonpolar solution.
	A)	The phospholipid heads would orient toward the solution.
	B)	The phospholipid tails would orient toward the solution.
	C)	The phospholipids would form a bilayer.
	D)	The phospholipid would form a liposome.

39.	Which of the following lipid composition options has the LEAST membrane fluidity?
	A)	phospholipids with long-chain, saturated fatty acids
	B)	phospholipids with long-chain, unsaturated fatty acids
	C)	phospholipids with short-chain, saturated fatty acids
	D)	phospholipids with short-chain, unsaturated fatty acids

40.	A single molecule is always either hydrophobic or hydrophilic, and can never possess (at the same time) a region that is hydrophobic and a region that is hydrophilic.
	A)	True
	B)	False

41.	A researcher is using a modified version of FRAP. She has devised a technique that allows her to label all the peripheral membrane proteins with a fluorescent tag, and has bleached a specific area of the cell membrane. After 24 hours, she notices that fluorescence has returned to the bleached area. What can she deduce from this experiment?
	A)	Peripheral membrane proteins may not be permanently associated with the cell membrane.
	B)	Peripheral membrane proteins—like transmembrane proteins—are located within the cell membrane.
	C)	Peripheral membrane proteins can move freely within the cell membrane.
	D)	Peripheral membrane proteins are akin to integral membrane proteins.
	E)	Peripheral membrane proteins can both move freely within the cell membrane and are akin to integral membrane proteins.

42.	Imagine a cell that has a membrane composed mostly of lipids with saturated fatty acid tails, and that this membrane also has low cholesterol content. What are the characteristics of this cell membrane?
	A)	The lipids would be able to easily transition between the inner and outer layers of the bilayer constituting the cell membrane.
	B)	The lipids contained in such a membrane would be highly mobile, and in near constant flux.
	C)	Due to its cholesterol content, the cell membrane would remain fluid even at cold temperatures.
	D)	The characteristics of this cell membrane will closely mirror those of a membrane composed of only unsaturated fatty acids.
	E)	None of the answer options is correct.

43.	If cells had single-layer membranes like micelles, how would the structures of transmembrane proteins be affected?
	A)	Transmembrane proteins would only possess hydrophobic regions.
	B)	Transmembrane proteins would only possess hydrophilic regions.
	C)	Transmembrane proteins would possess a hydrophobic region in the cell interior and a hydrophilic region in the extracellular space.
	D)	Transmembrane proteins would possess a hydrophilic region in the cell interior and a hydrophobic region in the extracellular space.
	E)	The structures of transmembrane proteins would remain the same as if cells had lipid bilayers.

44.	Which one of the following molecules would MOST likely require a transport protein to cross the plasma membrane of a red blood cell?
	A)	CO2
	B)	H2O
	C)	O2
	D)	C6H12O6

45.	Explain why the plasma membrane is permeable to some substances, while others require a channel, or carrier, protein to cross the membrane.

46.	Some diseases result from defective transport across the membrane. For example, cystic fibrosis results when a chloride ion transporter does not function. Which of the following is affected when this transporter does NOT function?
	A)	the chloride concentration gradient
	B)	the electrical gradient of the cell
	C)	both the chloride concentration gradient and the electrical gradient of the cell
	D)	neither the chloride gradient nor the electrical gradient of the cell

47.	Suppose you are studying the transport of a certain polar molecule across the plasma membrane of cells in culture. Over a period of time, you measure the concentration of a polar molecule inside and outside of the cells. You find that the concentration of the molecule is lower in the cell but is gradually increasing. You also measure the ATP concentration inside the cell and find that it is not changing. Which of the following is probably responsible for the transport of this polar substance into the cell?
	A)	facilitated diffusion
	B)	secondary active transport
	C)	endocytosis
	D)	active transport
	E)	simple diffusion

48.	Suppose you are studying the transport of a certain polar molecule across the plasma membrane of cells in culture. Over a period of time, you measure the concentration of a polar molecule inside and outside of the cells. You find that the concentration of the molecule is higher in the cell and is gradually increasing. You also measure the ATP concentration inside the cell and find that it is decreasing. Which of the following is probably responsible for the transport of this polar substance into the cell? (Select all that apply.)
	A)	facilitated diffusion
	B)	secondary active transport
	C)	endocytosis
	D)	active transport
	E)	simple diffusion

49.	The beaker in the illustration below contains two solutions of salt with different concentrations (measured by molarity, M). The two solutions are separated by a membrane that is permeable to both salt and water. Which of the following will occur in this container?
	A)	Net diffusion of water from B to A and of salt from A to B.
	B)	Net diffusion of water from A to B and of salt from B to A.
	C)	Net diffusion of water across the membrane, but not of salt.
	D)	Diffusion of salt across the membrane, but not of water.
	E)	Net diffusion of salt from B to A, but no net diffusion of water.

50.	The beaker in the illustration below contains two solutions of salt with different concentrations (measured by molarity, M). The two solutions are separated by a membrane that is permeable to both salt and water. Which of the following will occur in this container?
	A)	Diffusion of water from B to A and of salt from A to B.
	B)	Net diffusion of water across the membrane, but not of salt.
	C)	Diffusion of salt across the membrane, but not of water.
	D)	Net diffusion of salt from B to A, but no net diffusion of water.

51.	Some drugs are now being delivered into cells through liposomes, in which the drug is surrounded by a phospholipid bilayer. How do the drugs enter into the cell?
	A)	The drug destroys the liposome and diffuses into the cell.
	B)	The liposome cuts a hole in the cell membrane and injects the drug into the cell.
	C)	The liposome fuses with the phospholipid bilayer of the cell.
	D)	Protein channels on the cell surface transport the liposomes into the cell.

52.	Some drugs are now being delivered into cells through liposomes, in which the drug is surrounded by a phospholipid bilayer. Explain how the drugs enter the cell.

53.	The plasma membranes of some plant cells use transport proteins to move protons out of the cell against their concentration gradient. This is an example of:
	A)	facilitated diffusion.
	B)	passive transport.
	C)	endocytosis.
	D)	active transport.
	E)	simple diffusion

54.	Which of the following represents the order that molecules cross a synthetic membrane composed of phospholipids but not proteins, from most easily (freely permeable) to least easily (not permeable)?
	A)	O2, sodium ions (Na+), water (H2O), glucose
	B)	O2, water (H2O), glucose, sodium ions (Na+)
	C)	sodium ions (Na+), glucose, water (H2O), O2
	D)	water (H2O), glucose, sodium ions (Na+), O2
	E)	glucose, water (H2O), O2, sodium ions (Na+)

55.	G protein-coupled receptors are transmembrane receptors involved in cell signaling. The amino acid sequence of these proteins reveals that the polypeptide chain of the protein has seven hydrophobic regions. Based on this information, what can you conclude about how the protein is associated with the cell membrane?
	A)	The receptor is likely to be a peripheral membrane protein.
	B)	The polypeptide chain is likely to span the membrane once.
	C)	The polypeptide chain is likely to span the membrane seven times.
	D)	The polypeptide chain is likely to span the membrane fourteen times.
	E)	The receptor is likely to be synthesized on free ribosomes.

56.	Some plant cells take advantage of the high concentration of protons outside the cell to move solutes, such as sucrose, across the plasma membrane into the cell where the sucrose concentration is already relatively high. This type of transport is an example of:
	A)	facilitated diffusion.
	B)	osmosis.
	C)	secondary active transport.
	D)	passive transport.

57.	Which of the following is responsible, in part, for keeping the cytoplasm of red blood cells isotonic with the blood plasma, and thereby preventing either lysis or shrinking of the cells?
	A)	facilitated diffusion
	B)	sodium channels
	C)	the sodium/potassium pump
	D)	osmosis

58.	The active maintenance of a constant internal environment is referred to as:
	A)	homeostasis.
	B)	equilibrium.
	C)	stability.
	D)	symmetry.
	E)	balance.

59.	The electrical component of an electrochemical gradient is due to:
	A)	the use of ATP as an energy source to drive primary transport.
	B)	a greater concentration of positive charges on the side of the membrane with the lowest concentration of protons.
	C)	a higher pH on the side of the membrane with the highest concentration of protons.
	D)	a higher pH on the side of the membrane with the lowest concentration of protons.
	E)	a greater concentration of positive charges on the side of the membrane with the highest concentration of protons.

60.	A beaker contains two solutions of salt dissolved in water. The two solutions have different concentrations (measured by molarity, M) and are separated by a membrane that is permeable to both salt and water. Which of the following statements is TRUE?
	A)	There will be a net movement of salt from side A to side B
	B)	There will be a net movement of salt, but net movement of water will not occur.
	C)	There is more water in side A than there is in side B.

61.	In intestinal epithelial cells, a transport protein moves glucose into the cytoplasm against its concentration gradient at the same time that it transports Na+ into the cell down its electrochemical gradient. Which of the following CORRECTLY describes this cotransport of glucose and sodium?
	A)	Primary active transport by a symporter.
	B)	Secondary active transport by an antiporter.
	C)	Secondary active transport by a symporter.
	D)	Primary active transport by an antiporter.

62.	The sodium-potassium pump is an example of:
	A)	a symporter.
	B)	passive transport.
	C)	an antiporter.
	D)	channel-mediated diffusion.
	E)	None of the answer options is correct.

63.	The MOST abundant organic molecule in nature is:
	A)	water.
	B)	cellulose.
	C)	aquaporin.
	D)	cholesterol.
	E)	ATP.

64.	Which of the following represents how easily the molecules cross a synthetic membrane composed of phospholipids but not proteins, from most easily (freely permeable) to least easily (not permeable)?
	A)	hydrophobic molecules, ions, small polar molecules, large polar molecules
	B)	hydrophobic molecules, small polar molecules, large polar molecules, ions
	C)	ions, large polar molecules, small polar molecules, hydrophobic molecules
	D)	small polar molecules, large polar molecules, ions, hydrophobic molecules
	E)	large polar molecules, small polar molecules, hydrophobic molecules, ions

65.	A beaker contains two solutions of salt dissolved in water. The two solutions have different concentrations (measured by molarity, M) and are separated by a membrane that is permeable to both salt and water. Which of the following statements is TRUE?
	A)	Side A is hypotonic relative to side B.
	B)	Side A is isotonic relative to side B.
	C)	Side A is hypertonic relative to side B.

66.	A beaker contains two solutions of glucose dissolved in water. The two solutions have different concentrations (measured by molarity, M) and are separated by a membrane that is permeable to water, but not to glucose. Which of the following statements is TRUE?
	A)	There will be net movement of glucose from B to A.
	B)	The volume will increase in side B of the beaker.
	C)	There will be net movement of water from B to A.
	D)	The system will not reach equilibrium.

67.	You are studying the transport of a particular substance into epithelial cells grown in culture. You notice that you can only find the substance inside the cell when ATP is present. How is the protein moving through the membrane?
	A)	diffusion
	B)	facilitated diffusion
	C)	passive transport
	D)	active transport

68.	Which way does the water move if the cell is in a hypotonic environment?
	A)	out of the cell
	B)	into the cell
	C)	Water doesn’t move across the hydrophobic core of cell membranes.

69.	In certain cells, a transport protein moves one calcium ion out of the cell against its concentration gradient while allowing the movement of three sodium ions into the cell down sodium’s electrochemical gradient. Which of the following CORRECTLY describes this cotrannsport of calcium and sodium?
	A)	primary active transport by a symporter
	B)	secondary active transport by an antiporter
	C)	secondary active transport by a symporter
	D)	primary active transport by an antiporter

70.	Which of the following have cell walls? (Select all that apply.)
	A)	plant cells
	B)	animal cells
	C)	fungal cells
	D)	bacterial cells

71.	Which of the following organisms have complex carbohydrates as a major component of their cell walls? (Select all that apply.)
	A)	animals
	B)	bacteria
	C)	fungi
	D)	plants

72.	On most bicycles, the tires include a separate inner tube inside the tire itself. When the inner tube is inflated, often to pressure greater than 100 pounds per square inch, it does not burst because the walls of the tire support it. Without the tire, the inner tube would burst long before such high pressures were reached. Similarly, the cytoplasm of plant cells in hypotonic conditions is under relatively high osmotic pressure. However, the cells do not lyse (or burst) due to the presence of the _____ that provides structural support for the _____.
	A)	cell wall; plasma membrane
	B)	cell wall; contractile vacuoles
	C)	plasma membrane; contractile vacuoles
	D)	contractile vacuoles; plasma membrane
	E)	contractile vacuole; cell wall

73.	Which one of the following is LEAST likely to cross a lipid bilayer?
	A)	O2
	B)	CO2
	C)	ATP
	D)	H2O
	E)	N2

74.	Passive transport of a molecule across a lipid bilayer only occurs if there is a significant difference in the concentration of that molecule from one side of the bilayer to the other.
	A)	True
	B)	False

75.	The movement of water across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration is referred to as _____.

76.	The random movement of molecules is referred to as:
	A)	transport.
	B)	osmosis.
	C)	diffusion.
	D)	All of these choices are correct.

77.	The term homeostasis refers to the ability of:
	A)	molecules to undergo net movement by diffusion.
	B)	the cell to seek out an optimal environment.
	C)	the plasma membrane to control what enters a cell.
	D)	the cell to control and maintain its internal environment.

78.	What factors are required for net movement of a substance to occur by facilitated diffusion?
	A)	a concentration gradient
	B)	a plasma membrane
	C)	a transport protein
	D)	All of these choices are correct.

79.	The movement of water into, or out of, a cell is an example of:
	A)	osmosis.
	B)	lysis.
	C)	diffusion.
	D)	active transport.
	E)	both osmosis and diffusion.

80.	Why does active transport require ATP?
	A)	An input of energy is needed to speed up the rate of facilitated diffusion.
	B)	An input of energy is needed to allow the movement of molecules from an area of low concentration to one of higher concentration.
	C)	An input of energy is needed to maintain the conformation of transport proteins.
	D)	An input of energy is needed to both speed up the rate of facilitated diffusion and maintain the conformation of transport proteins.

81.	What is the function of the contractile vacuole?
	A)	to help single-celled organisms maintain homeostasis in a hypotonic environment
	B)	to help single-celled organisms change shape in response to environmental changes
	C)	to help single-celled organisms maintain homeostasis in a hypertonic environment
	D)	to maintain cell shape through turgor pressure

82.	Turgor pressure is the result of:
	A)	the activity of the contractile vacuole.
	B)	water accumulation within a cell.
	C)	the rigidity of the plasma membrane.
	D)	All of these choices are correct.

83.	A cell’s plasma membrane contributes to homeostasis by:
	A)	acting as a selective barrier.
	B)	defining the boundary between the inside and outside of the cell.
	C)	functioning as a fluid mosaic of lipid and protein.
	D)	maintaining the shape of the cell.

84.	Which of the following molecules does NOT easily diffuse across a plasma membrane?
	A)	small polar molecules
	B)	large polar molecules
	C)	gases
	D)	both small and large polar molecules

85.	The process of diffusion requires:
	A)	a concentration gradient.
	B)	ATP.
	C)	the random movement of molecules.
	D)	transport proteins.

86.	Which one of the following is an example of secondary active transport?
	A)	the use of an electrochemical gradient of one molecule to move a second molecule
	B)	the movement of potassium ions following the initial movement of sodium ions
	C)	the use of more than one type of transport protein for the movement of a molecule
	D)	the use of a chemical gradient to generate an electrical gradient

87.	How is a carrier protein different from a channel protein?
	A)	Carrier proteins use ATP, but channel proteins do not.
	B)	Carrier proteins undergo conformational change so that they are open alternately to one side of the membrane or the other.
	C)	Transport through carrier proteins depends on concentration gradients, but transport through channel proteins does not.
	D)	Transport through a carrier does not depend on the random motion of molecules.

88.	During osmosis, water moves from a region of _____ to a region of _____.
	A)	high solute concentration; low solute concentration
	B)	high solvent concentration; low solvent concentration
	C)	low solute concentration; high solute concentration
	D)	Both “high solvent concentration; low solvent concentration” AND “low solute concentration; high solute concentration” are correct answers.

89.	How is the energy stored in a molecule of ATP used by the sodium-potassium pump?
	A)	It is used to transport potassium ions out of the cell.
	B)	It is used to transport sodium ions into the cell.
	C)	It is used to alter the conformation of the pump protein.
	D)	All of these choices are correct.

90.	What would be the outcome if the pump protein shown in Fig. 5.13a instead acted as a carrier that allowed protons to move from the extracellular fluid into the cytoplasm?
	A)	The proton electrochemical gradient would be reversed.
	B)	ATP could be synthesized from ADP + Pi.
	C)	The number of protons on either side of the membrane would equalize.
	D)	ATP could be synthesized from ADP + Pi and the number of protons on either side of the membrane would equalize.

91.	Which of the following is TRUE about the presence or absence of plasma membranes?
	A)	Only animal cells have a plasma membrane. Plant cells and bacterial cells have a cell wall.
	B)	Plant cells and bacterial cells have a plasma membrane, but animal cells do not.
	C)	Plant cells and animal cells have a plasma membrane, but bacterial cells do not.
	D)	All cells have a plasma membrane.

92.	Cells from which domain(s) of life are separated from their environment by a plasma membrane? (Select all that apply.)
	A)	archaea
	B)	bacteria
	C)	eukarya

93.	Which one of the following is NOT considered part of the cytoplasm?
	A)	the endoplasmic reticulum
	B)	the nucleus
	C)	the Golgi apparatus
	D)	the cytoskeleton
	E)	None of the answer options is correct.

94.	Which one of the choices below can be used to CORRECTLY complete the following sentence? “All _____ have a plasma membrane.”
	A)	cells
	B)	animal and plant cells, but not bacterial cells,
	C)	bacterial cells, but not animal and plant cells,
	D)	plant and bacterial cells, but not animal cells,

95.	Which one of the following organisms organizes its genome into a nucleoid?
	A)	fungi
	B)	plants
	C)	animals
	D)	archaea

96.	All cells have:
	A)	a nucleus.
	B)	genetic information.
	C)	internal compartments.
	D)	a cell wall.

97.	All of the following are properties of at least some prokaryotic cells EXCEPT:
	A)	a nucleus.
	B)	plasmids.
	C)	small size.
	D)	pili.

98.	Which eukaryotic organelle is associated with the breakdown of macromolecules?
	A)	endoplasmic reticulum
	B)	the Golgi apparatus
	C)	mitochondria
	D)	lysosome

99.	The genetic material of a prokaryotic cell is located in its:
	A)	nucleolus.
	B)	nucleus.
	C)	nucleoid.
	D)	nucleosome.

100.	How do eukaryotic plant and animal cells differ from one another?
	A)	Animal cells have mitochondria but not chloroplasts, and plant cells have chloroplasts but not mitochondria.
	B)	Animal cells do not have chloroplasts and cell walls, and plant cells do.
	C)	Animal cells have endoplasmic reticulum and plant cells don’t.
	D)	Animal cells have a plasma membrane and plant cells have a cell wall.

101.	Prokaryotes absorb their nutrients from the environment; however, prokaryotes also have cell walls. What can you conclude from these statements?
	A)	Cell walls are permeable, allowing nutrients to pass through.
	B)	Prokaryotes live in a hypertonic environment.
	C)	Osmosis drives the movement of nutrients through the cell wall.
	D)	Prokaryotic cell walls do not allow nutrients to pass through them.

102.	Bacteria are rarely larger than 1–2 mm in size, and are typically shaped like rods, spheres, or spirals. What likely accounts for the shape and size of these prokaryotes?
	A)	Such shapes likely make it difficult for predators to catch bacteria.
	B)	Such shapes can accommodate the complex arrangements of plasmids within bacteria.
	C)	Such shapes facilitate the formation of pili in bacteria.
	D)	Such shapes maximize the surface area over which nutrients can diffuse into bacteria.
	E)	Such shapes both facilitate the formation of pili in bacteria and maximize the surface area over which nutrients can diffuse into bacteria.

103.	Prokaryotes contain nucleoids, which are similar to nuclei in that they contain rudimentary chromosomes referred to as plasmids.
	A)	True
	B)	False

104.	Which of the following eukaryotic cell structures plays a role in protein trafficking and sorting?
	A)	mitochondria
	B)	lysosomes
	C)	the endoplasmic reticulum
	D)	the Golgi apparatus
	E)	vacuoles

105.	A researcher is very surprised to find a prokaryotic cell that is greater than 100 mm in diameter. How could this be possible?
	A)	A mutation has occurred that increases the size of the nucleoid by two, thereby allowing the cell to grow in diameter.
	B)	There may be a large vacuole in the cell, which allows nutrients to still reach all areas of the cytoplasm in the cell.
	C)	Plasmids within the cell carry mutations that allow the cell to grow larger in size.
	D)	Through pili interactions, the prokaryotic cell can grow larger in size.
	E)	A mutation has increased the size of the nucleoid by two, or the prokaryote can grow larger in size through pili interactions.

106.	Which of the following statements is TRUE regarding cytosol?
	A)	Cytosol contains, and includes, organelles.
	B)	Cytosol is the “jelly” substance within cells.
	C)	Cytosol excludes organelles.
	D)	Cytosol includes the nucleus.
	E)	Cytosol is the “jelly” substance within cells and it excludes organelles.

107.	Imagine that you have two blades of grass. One is from a normal plant, and the other is from a mutant plant that cannot produce vacuoles. How will the structures of these two blades of grass compare?
	A)	The grass blade from the mutant plant will appear limp compared to that from the normal plant.
	B)	The grass blade from the mutant plant will appear taller than that from the normal plant.
	C)	The grass blade from the mutant plant will be sturdier compared to that from the normal plant.
	D)	The grass blade from the mutant plant will appear unpigmented compared to that from the normal plant.
	E)	The grass blades from the mutant and normal plant will appear identical.

108.	If a cell lacked a cytoskeleton, which of the following would likely be a result?
	A)	The cell would be unable to harness energy.
	B)	The cell would be unable to carry out translation.
	C)	The shape of the cell would be impacted.
	D)	Protein movement in the cell would be affected.
	E)	The shape of the cell would be affected and protein movement in the cell would be affected.

109.	A bacterial cell, a plant cell, and an animal cell have which of the following structures in common?
	A)	nucleus
	B)	cell wall
	C)	vacuole
	D)	nucleoid
	E)	cytoplasm

110.	Which one of the following is MOST closely related to archaea?
	A)	eukaryotes
	B)	bacteria
	C)	both eukaryotes and bacteria
	D)	neither eukaryotes nor bacteria

111.	Which of the following sequences of events correctly describes the progress of a protein that will be secreted from the cell? 1. SRP binds to the growing polypeptide chain and to the ribosome. 2. Translation resumes. 3. SRP binds to its receptor. 4. The signal sequence is cleaved. 5. Protein synthesis begins in the cytosol. 6. Translation pauses.
	A)	5  1  6  3  2  4
	B)	5 ® 6 ® 1 ® 3 ® 2 ® 4
	C)	3 ® 6 ® 1 ® 2 ® 4 ® 5

112.

Put the following events in the CORRECT sequence for a protein that will be secreted from the cell. A. SRP binds to the growing polypeptide chain and to the ribosome. B. Translation resumes. C. SRP binds to its receptor. D. The signal sequence is cleaved. E. Protein synthesis begins in the cytosol. F. Translation pauses.

113.	If a mutation rendered the signal recognition particle nonfunctional, what would be the MOST obvious effect on the cell?
	A)	Translation would not be completed for most proteins.
	B)	All proteins normally secreted by the cell would remain partially formed and attached to the endoplasmic reticulum.
	C)	Proteins destined for the nucleus would remain in the cytosol.
	D)	No proteins would arrive at their proper destinations within the cell.
	E)	All proteins normally secreted by the cell would remain in the cytosol.

114.	Which of the following accurately describes the path traveled by a new protein as it is synthesized and released from the cell?
	A)	plasma membrane  ER  vesicle  Golgi  cytosol  external environment
	B)	cytosol ® ER ® Golgi ® vesicle ® plasma membrane ® external environment
	C)	nuclear envelope ® ER ® vesicle ® Golgi ® plasma membrane ® external environment
	D)	cytosol ® Golgi ® ER ® vesicle ® plasma membrane ® external environment
	E)	nucleus ® ER ® Golgi ® vesicle ® plasma membrane ® external environment

115.	List in order each compartment that a secreted protein passes through from its initial synthesis until it is released to the outside of the cell.

116.

From the following list of compartments and locations in the cell, build a pathway that a protein would follow from its initial synthesis to its secretion. Not all structures/compartments listed will necessarily be used. endoplasmic reticulum transport vesicle lysosome Golgi apparatus mitochondrion nucleus cytosol plasma membrane cell wall chloroplast

117.

Imagine that you are investigating the production of insulin in normal cells to help determine the cause of faulty insulin production in cells in which insulin appears to be synthesized but fails to be secreted from the cell. You design experiments using three different pharmaceutical compounds to help pinpoint the trouble spot in the protein synthetic pathway. The first compound blocks the movement of transport vesicles in the cytoplasm. The second blocks SRP release from the ribosome and mRNA. The third compound binds to and blocks the signal sequence so that the SRP cannot recognize it. For each of these three treatments, indicate (1) whether the protein would be made at all, and if so, (2) where in the cell you would find it.

118.	Some diseases, such as Tay-Sachs, are caused by the defective breakdown of cellular components. Which of the following organelles is defective?
	A)	plasma membrane
	B)	ribosome
	C)	endoplasmic reticulum
	D)	Golgi apparatus
	E)	lysosome

119.	Disorders of which organelle are often associated with defects in transport from compartment to compartment, resulting in poor sorting of protein components within the cell?
	A)	plasma membrane
	B)	plasmids
	C)	endoplasmic reticulum
	D)	the Golgi apparatus
	E)	nucleus

120.	Many cellular disorders exist in which the synthesis of certain proteins and their transport to specific locations in the cell are affected. Which organelles are involved in these disorders and why?

121.	You are investigating a particular cell type, and you notice that a protein normally found in the lysosome ends up being secreted from the cell. This appears to be the only thing wrong with these cells. Of the following conditions, which is the MOST likely cause of this defect in these cells?
	A)	The lysosome leaks the protein out of the cell.
	B)	One of the signal sequences on the lysosomal protein is defective.
	C)	Transport vesicles responsible for sorting in the cell are defective.
	D)	The pH of the lysosome is not low enough for the protein to remain in it.

122.	You are investigating a particular cell type, and you notice that a protein normally found in the lysosome ends up being secreted out of the cell. This appears to be the only thing wrong with these cells. Suggest a defect that could explain this observation.

123.	Insulin is a protein hormone that helps to control the level of glucose in the blood. It is secreted from specialized cells in the pancreas. Based on this information, which path does insulin take out of the cell?
	A)	ER membrane  vesicle membrane  plasma membrane  exterior of cell
	B)	vesicle ® ER ® Golgi apparatus ® exterior of cell
	C)	nucleus ® ER ® Golgi apparatus ® vesicle ® exterior of cell
	D)	ER ® Golgi apparatus ® vesicle ® exterior of cell
	E)	ER ® nucleus ® cytosol ® exterior of cell

124.	When physicians perform organ transplants, they make sure that there is a match between the donor (the person donating the organ) and the recipient (the person receiving the organ). What feature of the cell is being matched?
	A)	phospholipids in the plasma membrane
	B)	cholesterol in the plasma membrane
	C)	protein channels in the plasma membrane
	D)	proteins pumps in the plasma membrane
	E)	glycyoproteins in the plasma membrane

125.	During the translation of mRNA molecules, the new polypeptides are often directed to specific parts of the cell by the presence or absence of short sequences of amino acids called signal peptides. Which of the following would you expect to find in the polypeptide that will eventually fold to become a histone protein?
	A)	no signal peptide
	B)	an amino terminal signal peptide
	C)	an internal signal peptide
	D)	a signal anchor peptide

126.	During the translation of mRNA molecules, the new polypeptides are often directed to specific parts of the cell by the presence or absence of short sequences of amino acids called signal peptides. Which of the following would you expect to find in the polypeptide that will eventually fold to become an ion channel protein?
	A)	no signal peptide
	B)	an amino terminal signal peptide
	C)	an internal signal peptide
	D)	a signal anchor peptide

127.	During the translation of mRNA molecules, the new polypeptides are often directed to specific parts of the cell by the presence or absence of short sequences of amino acids called signal peptides. Which of the following would you expect to find in the polypeptides that will eventually fold to become ribosomal proteins?
	A)	no signal peptide
	B)	an amino terminal signal peptide
	C)	an internal signal peptide
	D)	a signal anchor peptide

128.	During the translation of mRNA molecules, the new polypeptides are often directed to specific parts of the cell by the presence or absence of short sequences of amino acids called signal peptides. Which of the following would you expect to find in the polypeptides that will eventually fold to become enzymes important in photosynthesis, such as NADP+ reductase?
	A)	no signal peptide
	B)	an amino terminal signal peptide
	C)	an internal signal peptide
	D)	a signal anchor peptide

129.	With which of the following is a signal-recognition particle (SRP) capable of interacting? (Select all that apply.)
	A)	an SRP receptor
	B)	a ribosome
	C)	a signal sequence in a protein destined for the ER

130.	Which one of the following cellular compartments does NOT have a double membrane structure separating it from the rest of the cell?
	A)	lysosomes
	B)	the nucleus
	C)	mitochondria

131.	If a mutation rendered the signal recognition particle receptor nonfunctional such that it is no longer able to dissociate from the SRP, what would be the most obvious effect on the cell?
	A)	Translation of most proteins would be incomplete.
	B)	All proteins normally secreted by the cell would remain partially formed and attached to the endoplasmic reticulum.
	C)	Proteins destined for the nucleus would remain in the cytosol.
	D)	No proteins would arrive at their proper destinations within the cell.
	E)	All proteins normally secreted by the cell would remain in the cytosol.

132.

The signal recognition particle and its receptor on the surface of the endoplasmic reticulum ensure that proteins destined for incorporation into cellular membranes or for export from the cell are translated into the endoplasmic reticulum so that they may be processed through the endomembrane system. If a mutation rendered the signal recognition particle receptor nonfunctional such that the receptor was no longer able to dissociate from the SRP, what would be the most obvious effect on the cell?

133.	Which of the following would be synthesized in and processed by the rough endoplasmic reticulum and Golgi apparatus?
	A)	fatty acids and phospholipids
	B)	DNA polymerase and RNA polymerase
	C)	lysosomal enzymes
	D)	cytoskeletal proteins, actin and tubulin, which are found in the cytoplasm

134.	Which of the following are processed in the Golgi apparatus? (Select all that apply.)
	A)	integral membrane proteins of the plasma membrane
	B)	proteins that are secreted from the cell
	C)	proteins that will be broken down by lysosomes
	D)	mRNA molecules for the removal of introns
	E)	enzymes required for the synthesis of phospholipids

135.	RNA molecules are transported from the nucleus to the cytoplasm in eukaryotes through:
	A)	sodium-potassium pumps.
	B)	aquaporins.
	C)	passive diffusion.
	D)	budding off of the nuclear envelope.
	E)	nuclear pores.

136.	Which one of the following is moved from one side of a lysosomal membrane to the other by a transport protein in the lysosomal membrane?
	A)	protons
	B)	broken-down macromolecules
	C)	enzymes capable of breaking down macromolecules being delivered from the Golgi apparatus
	D)	protons and broken-down macromolecules

137.	A protein with an internal signal sequence is MOST likely to be located in:
	A)	the nucleus.
	B)	a mitochondrion.
	C)	the cytoplasm.
	D)	a chloroplast.
	E)	the extracellular space.

138.	In a eukaryotic cell, how does mRNA get out of the nucleus?
	A)	diffusion
	B)	through nuclear pores
	C)	through the endoplasmic reticulum
	D)	through the Golgi apparatus

139.	You notice in your experimental system that a particular protein is no longer entering the nucleus. What could have happened?
	A)	The signal sequence might be mutated.
	B)	The chaperone protein might have taken it to a different location.
	C)	The solute concentration might be higher inside the nucleus.
	D)	None of the other answer options is correct.

140.	A transmembrane protein in the outer membrane of the nuclear envelope would LEAST likely be found later in which one of the following cellular locations?
	A)	the plasma membrane
	B)	a lysosomal membrane
	C)	a mitochondrial membrane
	D)	the Golgi apparatus membrane
	E)	the rough endoplasmic reticulum membrane

141.	Which one of the following cell types would likely have the MOST extensive system of smooth endoplasmic reticulum?
	A)	skin cells
	B)	pancreatic cells that secrete digestive enzymes
	C)	testicular cells that secrete steroid hormones
	D)	central nervous system cells
	E)	muscle cells

142.	Which of the following organelles could be considered recycling centers of eukaryotic cells?
	A)	the nucleus
	B)	mitochondria
	C)	lysosomes
	D)	Golgi apparatus
	E)	smooth endoplasmic reticulum

143.	Which of the following is TRUE of lysosomes? (Select all that apply.)
	A)	The pH is often higher inside the lysosome than in the cytoplasm.
	B)	The concentration of protons in the lysosome is often higher than in the cytoplasm.
	C)	Proton pumps are sometimes found in the lysosomal membranes.
	D)	Lysosomes fuse with other vesicles that contain macromolecules targeted for breakdown.
	E)	Lysosomal membranes often contain proteins that transport amino acids, simple sugars, and nucleotides.

144.	During the translation of mRNA molecules, the new polypeptides are often directed to specific parts of the cell by the presence or absence of short sequences of amino acids called signal peptides. Which of the following would you expect to find in the polypeptides that will eventually fold to become the cytoskeletal proteins tubulin and actin, which are found in the cytoplasm?
	A)	no signal peptide
	B)	an amino terminal signal peptide
	C)	an internal signal peptide
	D)	a signal anchor peptide

145.	During the translation of mRNA molecules, the new polypeptides are often directed to specific parts of the cell by the presence or absence of short sequences of amino acids called signal peptides. Which of the following would you expect to find in the polypeptide that will eventually fold to become RNA polymerase?
	A)	no signal peptide
	B)	an amino terminal signal peptide
	C)	an internal signal peptide
	D)	a signal anchor peptide

146.	During the translation of mRNA molecules, the new polypeptides are often directed to specific parts of the cell by the presence or absence of short sequences of amino acids called signal peptides. Which of the following would you expect to find in the polypeptides that will eventually fold to become enzymes important in the citric acid cycle, such as the enzyme citrate synthase, which makes citric acid?
	A)	no signal peptide
	B)	an amino terminal signal peptide
	C)	an internal signal peptide
	D)	a signal anchor peptide

147.	During the translation of mRNA molecules, the new polypeptides are often directed to specific parts of the cell by the presence or absence of short sequences of amino acids called signal peptides. Which of the following would you expect to find in the polypeptide that will eventually fold to become a receptor protein?
	A)	no signal peptide
	B)	an amino terminal signal peptide
	C)	an internal signal peptide
	D)	a signal anchor peptide

148.	The process of a vesicle fusing with the plasma membrane and depositing its contents into the extracellular space is referred to as:
	A)	active transport.
	B)	endocytosis.
	C)	budding.
	D)	exocytosis.
	E)	bridging.

149.	In which of the following regions of the cell can protein synthesis occur in eukaryotes? (Select all that apply.)
	A)	cytoplasm
	B)	rough endoplasmic reticulum
	C)	nucleus
	D)	Golgi apparatus
	E)	lysosomes

150.	The Golgi apparatus is responsible for at least a portion of a eukaryote’s: (Select all that apply.)
	A)	carbohydrate synthesis.
	B)	modification of lipids synthesized in the ER.
	C)	targeting of proteins to their final destinations.
	D)	modification of proteins synthesized in the ER.

151.	Which of the following is part of the endomembrane system of a eukaryotic cell?
	A)	nuclear envelope
	B)	the Golgi apparatus
	C)	vesicles
	D)	All of these choices are correct.

152.	The controlled release of cellular material stored in membrane-bound vesicles to the outside of the cell is an example of:
	A)	exocytosis.
	B)	endocytosis.
	C)	transcytosis.
	D)	phagocytosis.

153.	Where are ribosomes found inside a cell?
	A)	attached to the Golgi apparatus
	B)	in the cytosol
	C)	attached to the rough endoplasmic reticulum
	D)	both in the cytosol and attached to the rough endoplasmic reticulum

154.	What is glycosylation?
	A)	the destruction of proteins in the lysosome
	B)	the process of vesicle transport between the cisternae of the Golgi apparatus
	C)	the addition of sugars to lipids or proteins
	D)	the attachment of an SRP to the signal sequence

155.	A lysosomal enzyme works best at a pH of:
	A)	3.
	B)	5.
	C)	7.
	D)	8.

156.	Where is the SRP receptor located in a cell?
	A)	in the membrane of the rough endoplasmic reticulum
	B)	in the membrane of the Golgi apparatus
	C)	in the nuclear envelope
	D)	in the membrane of the lysosome

157.	A nuclear pore is MOST similar to a:
	A)	pump protein.
	B)	channel protein.
	C)	carrier protein.
	D)	symporter protein.

158.	Which of the following would NOT be synthesized on the endoplasmic reticulum?
	A)	cytoskeletal proteins
	B)	lipids
	C)	pump proteins
	D)	lysosomal proteins

159.	Where are lysosomal enzymes synthesized?
	A)	on the rough endoplasmic reticulum
	B)	in the cytosol
	C)	on the Golgi apparatus
	D)	in a vesicle

160.	A proton pump is needed in the lysosomal membrane because:
	A)	the interior of the lysosome needs to be acidic.
	B)	protons are being moved from low to high concentration.
	C)	protons cannot move across a membrane on their own.
	D)	All of these choices are correct.

161.	MOST proteins containing a signal sequence located at their amino terminal ends are sorted to:
	A)	the cytosol.
	B)	the nucleus.
	C)	a mitochondrion or the rough endoplasmic reticulum.

162.	Which of the following is NOT a function of the signal recognition particle (SRP)?
	A)	halts translation
	B)	binds to the ribosome
	C)	binds to a channel in the rough endoplasmic reticulum
	D)	targets certain proteins to be synthesized on the rough endoplasmic reticulum

163.	A vesicle is most similar to a:
	A)	micelle.
	B)	lipid raft.
	C)	liposome.
	D)	bilayer.

164.	What accounts for the ability of vesicles to fuse with different membrane compartments in the cell?
	A)	the cell’s cytoskeleton
	B)	the fluid nature of the phospholipid bilayer
	C)	peripheral membrane proteins
	D)	transport proteins

165.	Imagine you have radioactively labeled a protein in the lumen of the endoplasmic reticulum. Where would you predict the labeled protein will end up?
	A)	in the lumen of the Golgi apparatus
	B)	in the lumen of a vesicle
	C)	outside the cell
	D)	All of these choices are correct.

166.	Enzymes present in the lumen of the Golgi apparatus are responsible for modifying proteins and lipids. What is the likely origin of these enzymes?
	A)	free ribosomes
	B)	the rough endoplasmic reticulum
	C)	the smooth endoplasmic reticulum
	D)	the cytosol

167.	Synthesis of a protein destined to function in the nucleus occurs:
	A)	in the cytosol.
	B)	on the rough endoplasmic reticulum.
	C)	on the outer leaf of the nuclear envelope.
	D)	in the Golgi apparatus.

168.	Transmembrane proteins MUST have:
	A)	a signal sequence.
	B)	a signal-anchor sequence.
	C)	a nuclear localization sequence.
	D)	both a signal sequence and a signal-anchor sequence.

1. Kangaroo rats live in the desert of the southwestern United States. They have many adaptations to minimize water loss. They obtain a small amount of water from seeds that they eat. However, the rest of the water they obtain is from cellular respiration.
2. A) This cannot be true, as cellular respiration doesn’t really “produce” water.
3. B) This cannot be true, as water is actually consumed in cellular respiration.
4. C) This could be true, as water is produced in cellular respiration.
5. D) This could be true, as water is produced in glycolysis.
6. E) This could be true, as water is produced in the citric acid cycle.

1. When carbohydrates are oxidized, the C–H bonds of the carbohydrate become C=O bonds of carbon dioxide. Oxidation is defined as a loss of electrons, but carbon does not become positively charged in the process. Why then is this considered oxidation?
2. A) The shared electrons in C–O bonds spend less time close to the carbon nucleus than the shared electrons in C–H bonds.
3. B) Electrons in the C=O bonds are higher energy than the electrons in the C–H bonds.
4. C) C=O bonds in CO2 are double bonds, and C–H bonds are single bonds.
5. D) The phosphate groups of ATP are ionized, and carbons donate those electrons.

1. Which of the following is/are TRUE regarding redox reactions? (Select all that apply.)
2. A) Oxidizing agents accept electrons.
3. B) If a molecule accepts electrons, it has been reduced.
4. C) Redox reactions may involve the transfer of hydrogen ions (H+).
5. D) A molecule that has gained H atoms is said to be reduced.
6. E) Reducing agents accept H atoms.
7. F) Oxidizing agents accept H+ ions.

1. Cellular respiration releases energy. In cellular respiration:
2. A) organic molecules such as carbohydrates are converted to chemical energy that can be used to do the work of the cell.
3. B) the chemical potential energy stored in organic molecules is converted to chemical energy that can be used to do the work of the cell.
4. C) chemical potential energy in the bonds of ADP is transferred to the chemical potential energy in the bonds of ATP.

1. An organism that carries out cellular respiration in its mitochondria:
2. A) may be a cell from a terrestrial (land) plant.
3. B) may be a prokaryotic cell from the domain Archaea.
4. C) is a bacterium.
5. D) may be any kind of cell.

1. In the reactions of glycolysis, pyruvate oxidation, and the citric acid cycle, chemical energy is transferred to the bonds in: (Select all that apply.)
2. A)
3. B) electron carriers.
4. C)
5. D) All of these choices are correct.

1. Complete oxidation of glucose to CO2 involves two different mechanisms for synthesizing ATP: oxidative phosphorylation and substrate-level phosphorylation. Which is TRUE of substrate-level phosphorylation?
2. A) An enzyme catalyzes the transfer of a phosphate group to ADP from an organic molecule to form ATP.
3. B) Most of the ATP generated in cellular respiration is generated by substrate-level phosphorylation.
4. C) ATP is generated indirectly through the transfer of high-energy electrons from electron carriers to an electron transport chain.
5. D) ATP is generated by release of energy from the electron carriers NADH and FADH2.

1. The energy in organic molecules is released in a series of steps because:
2. A) it is not possible to release it in a single step.
3. B) more total energy is released in multiple steps than would be released in a single step.
4. C) less total energy is released in multiple steps than would be released in a single step.
5. D) more energy can be harvested for cellular use in multiple steps than from a single step.
6. E) only a single electron can be moved at a time in a cellular reaction.

1. Some tissue types like brain tissue use glucose exclusively as an energy source.
2. A) True
3. B) False

1. The approximate yield of ATP molecules from the full oxidation of a molecule of glucose is:
2. A)
3. B)
4. C)
5. D)
6. E)

1. Consulting Figure 7.3 if necessary, during which stage(s) of cellular respiration is carbon dioxide released?

1. A) stage 1 only
2. B) stages 1 and 2
3. C) stages 2 and 3
4. D) stage 3 only
5. E) stages 3 and 4

1. In which form are electrons transferred during typical redox reactions such as the oxidation of glucose?
2. A) as free electrons
3. B) as hydrogen atoms
4. C) as oxygen atoms
5. D) as carbon atoms
6. E) as phosphate groups

1. Which of the following molecules has the GREATEST potential energy?
2. A) glucose
3. B) water
4. C) carbon dioxide

1. The rate of cellular respiration is constant in plants and animals, including humans.
2. A) True
3. B) False

1. Which is NOT a stage of cellular respiration?
2. A) citric acid cycle
3. B) glycolysis
4. C) oxidative phosphorylation
5. D) photosynthesis

1. Are electrons lost or gained in reduction?
2. A) lost
3. B) gained

1. Why do marathon runners “carbo load” (that is, eat a lot of pasta) before a big race?
2. A) They will feel full longer.
3. B) The bonds in carbohydrates have high potential energy.
4. C) The bonds in carbohydrates have low potential energy and can thus be broken down and readily consumed.
5. D) Through the process of anabolism, the athlete will break down the carbohydrates into smaller components, including ATP.

1. Energy can be extracted from glucose and converted to ATP only if: (Select all that apply.)
2. A) oxygen is the electron acceptor.
3. B) the cell has mitochondria.
4. C) the cell has membrane proteins that can pump hydrogen ions.
5. D) the cell has enzymes that can carry out oxidation-reduction reactions.
6. E) the cell has enzymes that can carry out glycolysis.

1. Which one of the following represents the REDUCED forms of the two major electron carriers?
2. A) NAD+ and FAD
3. B) NAD+ and FADH2
4. C) NADH and FAD
5. D) NADH and FADH2

1. The MOST stablethat is, least reactiveform of carbon is:
2. A)
3. B)
4. C)
5. D)
6. E) carbon dioxide.

1. Which one of the following is NOT a product of cellular respiration?
2. A) carbon dioxide
3. B) water
4. C) oxygen
5. D) ATP
6. E) All of these choices are correct.

1. The loss of electrons is referred to as _____.

1. The gain of electrons is referred to as _____.

1. Cellular respiration is a series of _____ reactions.
2. A) catabolic
3. B) anabolic
4. C) glycolytic
5. D) phosphorylation
6. E) carboxylation

1. The electron transport chain is part of:
2. A)
3. B) the citric acid cycle.
4. C) oxidative phosphorylation.
5. D)
6. E) pyruvate oxidation.

1. Which BEST describes energy production during cellular respiration?
2. A) A small amount of energy is produced by substrate-level phosphorylation; most is produced by oxidative phosphorylation.
3. B) A small amount of energy is produced by oxidative phosphorylation; most is produced by substrate-level phosphorylation.
4. C) An equal amount is produced by oxidative phosphorylation and substrate-level phosphorylation.
5. D) It depends on the organism. Some produce most of their energy by substrate-level phosphorylation, and some produce most of their energy by oxidative phosphorylation.
6. E) None of the other answer options is correct.

1. In the first three stages of cellular respiration, the chemical energy in glucose is transferred to:
2. A) ATP and cytochrome b.
3. B) electron carriers and ATP.
4. C) cytochrome b and coenzyme Q.
5. D) proton pumps and ATP.
6. E) only coenzyme Q.

1. Oxidation is the gain of electrons.
2. A) True
3. B) False

1. The _____ forms of the electron carriers NAD+/NADH and FADH/FADH2 have high potential energy.
2. A) oxidized
3. B) reduced
4. C) phosphorylated
5. D) carboxylated
6. E) None of the other answer options is correct.

1. In cellular respiration, oxygen:
2. A) gains electrons and is an oxidizing agent.
3. B) loses electrons and is a reducing agent.
4. C) gains electrons and is a reducing agent.
5. D) loses electrons and is an oxidizing agent.
6. E) None of the other answer options is correct.

1. In cellular respiration, glucose is _____ to CO2 and oxygen is _____ to water.
2. A) oxidized; reduced
3. B) reduced; oxidized
4. C) deoxygenated; phosphorylated
5. D) phosphorylated; deoxygenated
6. E) oxidized; oxidized

1. The chemical bonds of carbohydrates and lipids have high potential energy because:
2. A) they are strong oxidizing agents.
3. B) they are strong reducing agents.
4. C) many of these bonds are C—C and C—H bonds.
5. D) they are easy to phosphorylate.
6. E) they are easy to hydrolyze.

1. In a plant cell, all stages of cellular respiration are carried out in the cytoplasm.
2. A) True
3. B) False

1. Which of the following statements is TRUE regarding aerobic respiration?
2. A) Aerobic respiration requires oxygen at every stage of the process.
3. B) Aerobic respiration is carried out by all prokaryotes and eukaryotes.
4. C) Aerobic respiration is a three-stage process, with oxidative phosphorylation comprising the last stage.
5. D) Carbon dioxide is produced at every stage of aerobic respiration.
6. E) None of the other answer options is correct.

1. Which of the following statements is TRUE regarding the equation C6H12O6 + 6O2  6CO2 + 6H2O + energy?
2. A) The oxygen atoms in both CO2 and H2O are electronegative.
3. B) In the production of CO2 from glucose, the oxygen atoms lose electrons and the carbon atom is oxidized.
4. C) Glucose could be considered a reducing agent.
5. D) The movement of hydrogen atoms in reactions involving C6H12O6 and H2O yields no information regarding the movement of electrons.
6. E) The oxygen atoms in both CO2 and H2O are electronegative, and glucose is considered a reducing agent.

1. Which of the following statements is TREUE regarding a reducing agent?
2. A) It loses electrons.
3. B) It gains electrons.
4. C) It is an electron acceptor.
5. D) It is usually oxygen.
6. E) It is never oxidized.

1. When glucose is broken down in a cell, all of the energy it stores is released simultaneously, not in a stepwise process.
2. A) True
3. B) False

1. Which stage of cellular respiration occurs immediately after pyruvate is produced?
2. A) glycolysis
3. B) pyruvate oxidation
4. C) citric acid cycle
5. D) electron transport
6. E) oxidative phosphorylation

1. A molecule that is _____ loses electrons, and a molecule that is _____ gains electrons.
2. A) reduced; oxidized
3. B) negative; positive
4. C) oxidized; reduced
5. D) weak; polar
6. E) None of the other answer options is correct.

1. Glycolysis is a series of chemical reactions (endergonic and exergonic) by which the cell can obtain ATP. NAD+ plays a crucial role in the reactions of glycolysis by:
2. A) accepting electrons from glucose, with the result that glucose is partially oxidized to pyruvate.
3. B) donating electrons to pyruvate when glucose becomes partially oxidized.
4. C) converting endergonic reactions to exergonic reactions so that there is an output of energy to make ATP.
5. D) donating electrons to ADP to make ATP.

1. You are trying to find the maximum source of energy for an organism. Which of the following compounds would you choose?
2. A) glucose
3. B) oxygen
4. C) ATP
5. D) pyruvate
6. E) NADH

1. The phosphorylation of glucose during glycolysis serves to: (Select all that apply.)
2. A) destabilize the molecule, making it easier to cleave.
3. B) trap imported glucose inside the cell.
4. C) reduce an electron carrier, storing energy for later.

1. How many reactions in glycolysis directly generate ATP?
2. A) 1
3. B) 2
4. C) 3
5. D) 4
6. E) 5

1. Glycolysis results in the partial oxidation of glucose to pyruvate. This means that:
2. A) glucose combines with oxygen in the cytoplasm to get partially oxidized.
3. B) glucose is broken down partially to ATP in the cytoplasm.
4. C) glucose donates electrons directly to NAD+.
5. D) glycolysis consists only of exergonic reactions so that ATP can be made from the release of energy.
6. E) the electron carriers donate electrons to proteins in the mitochondria that in turn produce ATP.
7. F) in the process of the conversion of glucose to pyruvate, some potential energy is transferred to NADH and ATP.

1. Even though the full oxidation of glucose is exergonic, some of the reactions in cellular respiration are endergonic.
2. A) True
3. B) False

1. In eukaryotic cells, glycolysis occurs in:
2. A) the cytoplasm.
3. B) the nucleus.
4. C) the matrix of the mitochondria.
5. D) the endoplasmic reticulum.
6. E)

1. Which of the following is a net product of glycolysis? (Select all that apply.)
2. A) 2 pyruvate
3. B) 2 ATP
4. C) 2 NADH

1. Glycolysis is:
2. A)
3. B)
4. C) aerobic in some organisms but anaerobic in others.
5. D) aerobic in some tissues but anaerobic in others.
6. E) None of the other answer options is correct.

1. Which of the following is NOT one of the net final products of glycolysis?
2. A) two molecules of pyruvate
3. B) two molecules of ATP
4. C) two molecules of NADH
5. D) two molecules of acetyl-CoA

1. In glycolysis, ATP is synthesized by:
2. A) substrate-level phosphorylation.
3. B) oxidative phosphorylation.
4. C) both substrate level and oxidative phosphorylation.
5. D) electron carriers.
6. E) redox reactions.

1. The first phase of glycolysis requires the input of two ATP molecules. It is therefore:
2. A)
3. B)
4. C)
5. D)
6. E) None of the other answer options is correct.

1. Which of the following does NOT occur during the third phase of glycolysis?
2. A) pyruvate production
3. B) ATP synthesis
4. C) the transfer of high-energy electrons to NAD+
5. D) oxygen consumption
6. E) None of the other answer options is correct.

1. At the end of glycolysis, the carbon molecules originally found in the starting glucose molecule are in the form of:
2. A) one pyruvate molecule.
3. B) two pyruvate molecules.
4. C) two ATP molecules.
5. D) two NADH molecules.
6. E) four ATP molecules.

1. Phosphorylating glucose during phase 1 of glycolysis:
2. A) releases phosphorylated glucose from cells.
3. B) destabilizes the glucose molecule so that it can be broken down in phase 2.
4. C) provides electrons to reduce NAD+ in phase 3.
5. D) provides electrons to reduce FADH in phase 3.
6. E) None of the other answer options is correct.

1. In the second phase of glycolysis:
2. A) phosphate groups are added to glucose.
3. B) phosphorylated sugar molecule is cleaved and the products rearranged.
4. C) ATP is generated by substrate-level phosphorylation.
5. D) NAD+ is reduced to NADH.
6. E) ATP is generated by oxidative phosphorylation.

1. The inputs to glycolysis do NOT include: (Select all that apply.)
2. A)
3. B) NAD+.
4. C)
5. D)
6. E)

1. The ATP produced during glycolysis is the result of substrate-level phosphorylation.
2. A) True
3. B) False

1. During what phase of glycolysis is NADH formed?
2. A) during phase 1, when fructose 1,6-biphosphate is formed
3. B) during phase 2, when glyceraldehyde 3-phosphate is formed
4. C) during phase 3, when glyceraldehyde 3-phosphate is phosphorylated
5. D) during phase 3, when pyruvate is finally formed
6. E) during phase 1, when glucose is phosphorylated

1. Imagine that a eukaryotic cell carries a mutation impairing its ability to phosphorylate glucose during glycolysis. What is a likely result of this mutation?
2. A) High (possibly toxic) levels of glucose would accumulate in the cell.
3. B) Glucose could move out of the cell, slowing cellular respiration.
4. C) Because phosphorylation stabilizes glucose, glucose would spontaneously form pyruvate.
5. D) Without the phosphorylation of glucose, glycolysis would consist entirely of exergonic reactions.
6. E) More pyruvate would be formed at the end of glycolysis.

1. Although cellular respiration is typically thought of as an aerobic process, glycolysis itself is actually anaerobic.
2. A) True
3. B) False

1. Although glycolysis produces four molecules of ATP by substrate-level phosphorylation, the net gain of ATP for the cell is two molecules. This is due to the fact that glycolysis is—at first—endergonic.
2. A) True
3. B) False

1. How did the earliest organisms on Earth most likely produce ATP?
2. A) by pyruvate oxidation
3. B) by glycolysis
4. C) by the citric acid cycle
5. D) by oxidative phosphorylation

1. The reaction diagrammed here: (Select all that apply.)

1. A) is the final reaction of glycolysis.
2. B) is one possible pathway in the fermentation of pyruvate.
3. C) shows synthesis of the substrate that enters the citric acid cycle.
4. D) occurs in the cytosol.
5. E) occurs in the mitochondrial matrix.
6. F) occurs twice for each glucose oxidized.

1. What is the relationship between the reaction diagrammed here and glycolysis?

1. What is the relationship between the reaction diagrammed below and the citric acid cycle?

1. In eukaryotic cells, the oxidation of pyruvate occurs in:
2. A) the cytoplasm.
3. B) the nucleus.
4. C) the matrix of the mitochondria.
5. D) the endoplasmic reticulum.
6. E)

1. What glycolysis product is transported into the mitochondria?
2. A) ATP
3. B) NADP
4. C) pyruvate
5. D) glucose

1. In the reaction in the diagram below, pyruvate is converted to acetyl-CoA. Which if any of the following statements concerning this reaction is TRUE? (Select all that apply.)

1. A) CO2 is the most oxidized and therefore least energetic form of carbon.
2. B) NAD+ is more reduced than NADH.
3. C) NAD+ is an oxidizing agent.
4. D) This is not an oxidation/reduction reaction; that is, no electrons have moved.
5. E) This reaction harnesses the last of the remaining potential energy from glucose.

1. The conversion of pyruvate to acetyl-CoA does not produce any ATP directly. However, it does contribute to ATP production indirectly. How?

1. In eukaryotes, pyruvate oxidation takes place in the:
2. A)
3. B) outer mitochondrial membrane.
4. C) inner mitochondrial membrane.
5. D) intermembrane space of mitochondria.
6. E) mitochondrial matrix.

1. Pyruvate oxidation is an important stage in cellular respiration because it:
2. A) generates ATP by substrate-level phosphorylation.
3. B) transfers large numbers of electrons to electron carriers.
4. C) links glycolysis with the citric acid cycle.
5. D) eliminates toxic pyruvate from the cell.
6. E) is the first step in oxidative phosphorylation.

1. When a single pyruvate is converted to acetyl-CoA, the other products of the reaction are:
2. A) CO2 and ATP.
3. B) NADH and CO2.
4. C) ATP and NADH.
5. D) Pi and FADH2.
6. E) FADH2 and ATP.

1. Another name for acetyl-CoA synthesis is:
2. A)
3. B) pyruvate oxidation.
4. C) oxidative phosphorylation.
5. D) substrate-level phosphorylation.
6. E) pyruvate reduction.

1. During pyruvate oxidation, pyruvate is broken down into CO2 and an acetyl group. The CO2 is _____ than the acetyl group.
2. A) less oxidized
3. B) more reduced
4. C) more energetic
5. D) less energetic
6. E) None of the other answer options is correct.

1. After pyruvate oxidation, the chemical energy of how many carbons of the original glucose molecule is converted to chemical energy in the form of ATP in the remaining steps of cellular respiration?
2. A) 1
3. B) 2
4. C) 3
5. D) 4
6. E) 5

1. By the time pyruvate is formed, most of the energy contained in glucose has been released.
2. A) True
3. B) False

1. Which of the following statements is TRUE regarding pyruvate oxidation?
2. A) Like glycolysis, pyruvate oxidation is carried out in the mitochondria.
3. B) Pyruvate oxidation ends with the oxidation of an acetyl group, which forms CO2.
4. C) Pyruvate oxidation forms the same number of NADH (per glucose molecule) as glycolysis.
5. D) Pyruvate oxidation directly follows the citric acid cycle during cellular respiration.

1. During pyruvate oxidation, which of the following also occur(s)?
2. A) the formation of NADH
3. B) the oxidation of pyruvate
4. C) the formation of acetyl-CoA
5. D) the formation of CO2
6. E) All of these choices are correct.

1. Which of the following statements is TRUE regarding pyruvate and glucose?
2. A) Glucose easily passes in and out of mitochondria, and can often be found in the mitochondrial matrix.
3. B) Pyruvate is typically “trapped” in the intermembrane space of mitochondria, where it is oxidized to form acetyl-CoA.
4. C) Glucose and pyruvate are remarkably similar in structure, with both molecules possessing a ring shape.
5. D) Both glucose and pyruvate can feed directly into the citric acid cycle, although acetyl-CoA is the preferred reactant for this process.
6. E) None of the other answer options is correct.

1. Pyruvate oxidation produces a large amount of ATP.
2. A) True
3. B) False

1. In what organelle is pyruvate oxidation carried out in a cell?
2. A) chloroplast
3. B) nucleus
4. C) mitochondrion
5. D) Golgi apparatus
6. E) endoplasmic reticulum

1. Pyruvate oxidation is remarkably similar to glycolysis in that when one molecule of pyruvate enters into a mitochondrion, two molecules of acetyl-CoA are formed.
2. A) True
3. B) False

1. Like glycolysis, pyruvate oxidation produces both pyruvate and acetyl-CoA. These two products feed directly into the citric acid cycle and are the reactants for the cycle.
2. A) True
3. B) False

1. Which of the following statements is true regarding pyruvate oxidation?
2. A) This process occurs within the matrix of mitochondria.
3. B) This process constitutes the second stage of cellular respiration.
4. C) The process produces both CO2 and acetyl-CoA.
5. D) The process yields no ATP via substrate-level phosphorylation.
6. E) All of these choices are correct.

1. In step 6 of the citric acid cycle, succinate + FAD  fumarate + FADH2. Which statement concerning this reaction is/are TRUE? (Select all that apply.)
2. A) Fumarate is more oxidized than succinate.
3. B) FAD is more reduced than FADH2.
4. C) FAD is an oxidizing agent in the reaction.
5. D) This is not an oxidation/reduction reaction; that is, no electrons have moved.
6. E) None of the other answer options is correct.

1. Following the citric acid cycle but before the electron transport chain and oxidative phosphorylation, most of the energy from the original glucose molecule is found in:
2. A) acetyl-CoA.
3. B)
4. C)
5. D)
6. E)

1. Following the citric acid cycle but before the electron transport chain and oxidative phosphorylation, how much potential energy has been transferred to the bonds of ATP (at 7.3 kcal/mol)? the bonds of NADH (at 53 kcal/mol)? If glucose oxidation to CO2 and H2O has a G of 676 kcal/mol, what proportion of potential energy has been captured? Where would you predict the remaining potential energy has gone?

1. Each round of the citric acid cycle begins when the four-carbon molecule oxaloacetate is converted to the six-carbon molecule citrate. As the cycle progresses, two carbons are eliminated to regenerate the oxaloacetate. The added carbon is supplied by _____ and the two eliminated carbons are released as _____.
2. A) ATP; acetyl-CoA
3. B) CO2; pyruvate
4. C) acetyl-CoA; CO2
5. D) CO2; NADH
6. E) CO2; acetyl-CoA

1. Complete oxidation of glucose to CO2 involves two different mechanisms for synthesizing ATP: oxidative phosphorylation and substrate-level phosphorylation. Substrate-level phosphorylation: (Select all that apply.)
2. A) requires activity of the enzyme ATP synthase.
3. B) occurs in the mitochondria.
4. C) occurs across the inner mitochondrial membrane.
5. D) requires an electron transport chain.
6. E) occurs in the cytosol.

1. In 1937, two German biochemists published a paper proposing the following reactions as part of glucose oxidation:

citrate  isocitrate  -ketoglutarate  succinate  fumarate  malate  oxaloacetate

Adding succinate, fumarate, or malate to thin slices of tissue increased oxygen consumption, supporting the hypothesis that these molecules are intermediates in the process. However, a puzzling observation was that intermediates were still present in the reaction mixture at the end of the experiment. If they are intermediates, then they should be consumed as the next product in the pathway is formed. What explains this observation?

1. A) Succinate, fumarate, and malate are not reactants but catalysts, and catalysts are not consumed in the process.
2. B) Succinate, fumarate, and malate are constantly regenerated in the citric acid pathway.
3. C) Succinate, fumarate, and malate increase metabolism and therefore oxygen consumption, but they are not directly part of the glucose oxidation pathway.

1. Pyruvate can be used to produce: (Select all that apply.)
2. A)
3. B) acetyl-CoA.
4. C)

1. Acetate is the starting point for synthesis of a cell’s _____.

1. The citric acid cycle begins when acetyl-CoA combines with _____ to form _____.
2. A) pyruvate; citrate
3. B) malate; oxaloacetate
4. C) oxaloacetate; malate
5. D) oxaloacetate; citrate
6. E) citrate; cis-aconitate

1. Which of the following is a net product of the citric acid cycle for each molecule of pyruvate generated in glycolysis? (Select all that apply.)
2. A) 1 ATP
3. B) 3 NADH
4. C) 1 FADH2

1. Which of the following molecules has the GREATEST potential energy?
2. A) ATP
3. B) NADH
4. C) NAD+
5. D) FAD
6. E) FADH2

1. Order the following list of molecules according to their potential energy from high to low.
2. ATP
3. NADH
4. NAD+
5. FADH2

1. If an energy source such as sunlight is available, the citric acid cycle can run in reverse in some organisms.
2. A) True
3. B) False

1. In which stage of cellular respiration is the greatest amount of chemical energy harvested from molecules that are derived from food?
2. A) glycolysis
3. B) the conversion of pyruvate to acetyl-CoA
4. C) the citric acid cycle
5. D) the electron-transport chain

1. The citric acid cycle is believed to have developed fairly recently in the evolution of cellular life.
2. A) True
3. B) False

1. During the citric acid cycle:
2. A) fuel molecules are completely reduced.
3. B) ATP is synthesized by substrate-level phosphorylation.
4. C) high-energy electrons are removed from NAD+ and FADH.
5. D) ATP is synthesized by oxidative phosphorylation.

1. The citric acid cycle takes place in the:
2. A)
3. B) outer mitochondrial membrane.
4. C) inner mitochondrial membrane.
5. D) intermembrane space of mitochondria.
6. E) mitochondrial matrix.

1. The majority of the energy generated in the citric acid cycle is in the form of:
2. A) ATP produced by substrate-level phosphorylation.
3. B) GTP produced by substrate-level phosphorylation.
4. C) electrons donated to NAD+ and FAD+.
5. D) ATP produced by oxidative phosphorylation.
6. E) GTP produced by oxidative phosphorylation.

1. The citric acid cycle is a cycle because the starting molecule, _____, is regenerated at the end.
2. A) acetyl-CoA
3. B) oxaloacetate
4. C) fructose 6-diphosphate
5. D) pyruvate
6. E) citrate

1. Which of the following is NOT an end product for an acetyl group that enters the citric acid cycle?
2. A) ATP
3. B) NADH
4. C) FADH2
5. D) CO2
6. E) oxaloacetate

1. A single molecule of glucose requires _____ “turn(s)” through the citric acid cycle for its chemical energy to be completely harvested.
2. A) 1
3. B) 2
4. C) 3
5. D) 4
6. E) 5

1. ATP is not generated directly in the citric acid cycle; instead, an intermediate is first generated by substrate-level phosphorylation. The intermediate is:
2. A) acetyl-CoA.
3. B)
4. C)
5. D)
6. E)

1. During the citric acid cycle, the production of CO2 is the result of the _____ of intermediate compounds of the citric acid cycle coupled to the production of _____.
2. A) oxidation; NADH
3. B) oxidation; ATP
4. C) reduction; NADH
5. D) reduction; ATP
6. E) oxidation; GTP

1. Once they have been processed through the citric acid cycle, the acetyl-CoA molecules from a single glucose molecule produce:
2. A) 2 ATP, 6 NADH, 4 CO2.
3. B) 6 NADH, 6 GTP.
4. C) 6 FADH2, 2 ATP, 6 CO2.
5. D) 6 GTP, 6 FADH2.
6. E) 4 CO2, 6 FADH2, 2 ATP.

1. Malate is both the starting and ending product of the citric acid cycle.
2. A) True
3. B) False

1. Which is the ONLY reaction in the citric acid cycle that produces ATP by substrate-level phosphorylation?
2. A) the formation of fumarate
3. B) the formation of malate
4. C) the formation of citrate
5. D) the formation of succinate
6. E) the formation of oxaloacetate

1. Which of the following processes produces the HIGHEST number of reduced electron carriers and thus the GREATEST amount of ATP by oxidative phosphorylation?
2. A) the citric acid cycle
3. B) glycolysis
4. C) pyruvate oxidation
5. D) glycolysis and the citric acid cycle are tied for ATP production
6. E) None of the other answer options is correct.

1. Imagine that you exhale after a deep breath. Which of the following are you NOT exhaling?
2. A) CO2
3. B) waste products of glycolysis
4. C) waste products of pyruvate oxidation
5. D) waste products of the citric acid cycle
6. E) waste products of both pyruvate oxidation and the citric acid cycle

1. Recall that the citric acid cycle starts with a four-carbon molecule, but that most of its intermediates are molecules that contain six carbons. How is this possible?
2. A) through the reaction of succinate and succinyl-CoA
3. B) through the reaction of malate and oxaloacetate
4. C) through the reaction of acetyl-CoA and oxaloacetate
5. D) through the reaction of malate and fumarate
6. E) through the reaction of citrate and cis-aconitate

1. A researcher is studying a population of bacteria that carry out the citric acid cycle, but do so in reverse. What statements are likely TRUE of these bacteria?
2. A) An individual bacterium will produce most of its energy by means of the citric acid cycle.
3. B) These bacteria carry out cellular respiration in their mitochondria.
4. C) These bacteria will produce sugars from intermediates of the citric acid cycle.
5. D) These bacteria will release CO2 as a waste product.
6. E) These bacteria will release CO2 as a waste product and will carry out cellular respiration within their mitochondria.

1. Atractyloside is a poison that inhibits the transport of ADP from the cytosol across the mitochondrial membranes and into the mitochondrial matrix. The direct effect of this drug is to stop ATP synthesis because:
2. A) ADP is a necessary substrate for the reaction catalyzed by ATP synthase.
3. B) it prevents proton pumping across the inner mitochondrial membrane.
4. C) it prevents electron transfer to O2.
5. D) it prevents electron transfer from NADH to complex I.

1. Oligomycin is an antibiotic that binds ATP synthase, blocking the flow of protons through the enzyme’s proton channel. In addition to preventing synthesis of ATP, what additional effect might you expect in response to the presence of oligomycin?
2. A) higher pH in the intermembrane space
3. B) lower pH in the intermembrane space
4. C) a buildup of protons in the mitochondrial matrix

1. Very low concentrations of detergent make membranes leaky to small molecules and ions without damaging proteins. In isolated mitochondria exposed to detergent, the molecules of the electron transport chain and of ATP synthase remain intact. Do you expect ATP synthesis to continue in the presence of low concentrations of detergent?
2. A) Yes, because all enzymes and electron carriers are functional.
3. B) No, because with a leaky membrane, the proton gradient cannot be maintained.
4. C) No, because leaky membranes do not allow NADH and FADH2 to donate their electrons to the electron transport chain.
5. D) No, because leaky membranes inhibit glycolysis.

1. The pH in the intermembrane space of the mitochondria should be _____ compared with the matrix due to the concentration of protons in the intermembrane space.
2. A) lower; higher
3. B) higher; higher
4. C) higher; lower
5. D) lower; lower

1. Brown fat is a specialized tissue found in infants and hibernating mammals. Brown fat mitochondria have proton channels located in their inner membranes. What does this mean for the organism?
2. A) ATP production would be reduced because these organisms do not need as much energy.
3. B) Channels would contribute to the formation of the proton electrochemical gradient.
4. C) The potential energy of the proton electrochemical gradient would be released as heat.
5. D) There would be no effect.

1. A research group has discovered an organism with cells that contain a previously undescribed organelle. They do some tests on the isolated organelle to see if it is involved in any major metabolic reactions. To do this, they incubate these organelles for a period of time and determine changes in the amount of various substances in the suspending solution. The results follow.