Question 1

When an electron is transferred to a more electronegative atom

Accepted Answer

A)   it loses potential energy.
B)   it gains potential energy.
C)   it gains kinetic energy.
D)   it oxidizes the more electronegative atom.E) B) and D)
F) B) and C)

Question 2

Figure 7.2
-What happens at the end of the chain in Figure 7.2?

Accepted Answer

A)   Two electrons combine with a proton and a molecule of NAD+.
B)   Two electrons combine with a molecule of oxygen and two hydrogen atoms.
C)   Four electrons combine with a molecule of oxygen and four protons.
D)   Four electrons combine with four hydrogen and two oxygen atoms.
E)   One electron combines with a molecule of oxygen and a hydrogen atom.F) D) and E)
G) None of the above

Question 3

In alcohol fermentation, NAD+ is regenerated from NADH by

Accepted Answer

A)   oxidation of ethanol to acetaldehyde.
B)   oxidation of pyruvate to acetyl CoA.
C)   reduction of pyruvate to lactate.
D)   reduction of acetaldehyde to ethanol.
E)   reduction of acetyl CoA to ethanol.F) A) and B)
G) All of the above

Question 4

Figure 7.2
-Which of the protein complexes labeled with Roman numerals in Figure 7.2 will transfer electrons to O₂?

Accepted Answer

A)   complex I
B)   complex II
C)   complex III
D)   complex IV
E)   All of the complexes can transfer electrons to O₂.F) B) and E)
G) A) and E)

Question 5

Which catabolic processes may have been used by cells on ancient Earth before free oxygen became available?

Accepted Answer

A)   only glycolysis and fermentation
B)   only glycolysis and the citric acid cycle
C)   only glycolysis and pyruvate oxidation
D)   only oxidative phosphorylation, using an electron acceptor other than oxygen
E)   glycolysis, pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation, using an electron acceptor other than oxygenF) A) and E)
G) A) and D)

Question 6

Which metabolic pathway requires a proton gradient?

Accepted Answer

A)   the oxidation of pyruvate to acetyl CoA
B)   the citric acid cycle
C)   oxidative phosphorylation
D)   glycolysis
E)   fermentationF) D) and E)
G) A) and B)

Question 7

When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?

Accepted Answer

A)   The pH of the matrix increases.
B)   ATP synthase pumps protons by active transport.
C)   The electrons gain free energy.
D)   NAD+ is oxidized.E) All of the above
F) B) and D)

Question 8

When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is

Accepted Answer

A)   the formation of ATP.
B)   the reduction of NAD+.
C)   a decrease in the pH of the mitochondrial matrix.
D)   the creation of a proton-motive force.E) A) and B)
F) B) and D)

Question 9

When an individual is exercising heavily and the muscle becomes oxygen-deprived, muscle cells convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells?

Accepted Answer

A)   It is reduced and converted back to pyruvate in muscle cells.
B)   It is oxidized to CO₂ and water.
C)   It is taken to the liver and converted back to pyruvate.
D)   It oxidizes FADH₂ to FAD+.
E)   It is converted to alcohol.F) A) and B)
G) C) and E)

Question 10

The complete oxidation of glucose (C₆H₁₂O₆)  to carbon dioxide and water in aerobic respiration consumes how many molecules of oxygen (O₂) ?

Accepted Answer

A)   1
B)   3
C)   6
D)   12
E)   36F) A) and B)
G) B) and E)

Question 11

Which kind of metabolic poison would most directly interfere with glycolysis?

Accepted Answer

A)   an agent that reacts with oxygen and depletes its concentration in the cell
B)   an agent that binds to pyruvate and inactivates it
C)   an agent that closely mimics the structure of glucose but is not metabolized
D)   an agent that reacts with NADH and oxidizes it to NAD+
E)   an agent that blocks the passage of electrons along the electron transport chainF) A) and C)
G) A) and D)

Question 12

Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions of glycolysis?

Accepted Answer

A)   0%
B)   2%
C)   10%
D)   38%
E)   100%F) C) and D)
G) C) and E)

Question 13

In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve?

Accepted Answer

A)   It increases the surface area for glycolysis.
B)   It increases the surface area for the citric acid cycle.
C)   It increases the surface area for oxidative phosphorylation.
D)   It increases the surface area for substrate-level phosphorylation.E) None of the above
F) A) and C)

Question 14

Which of the following produces the most ATP when glucose (C₆H₁₂O₆)  is completely oxidized to carbon dioxide (CO₂)  and water?

Accepted Answer

A)   glycolysis
B)   fermentation
C)   oxidation of pyruvate to acetyl CoA
D)   citric acid cycle
E)   oxidative phosphorylation (chemiosmosis) F) None of the above
G) B) and C)

Question 15

Yeast cells grown anaerobically can obtain energy by fermentation, which results in the production of

Accepted Answer

A)   ATP, NADH, and pyruvate.
B)   ATP and lactate.
C)   ATP, CO₂, and lactate.
D)   ATP, CO₂, and ethanol.
E)   ATP, CO₂, and acetyl CoA.F) D) and E)
G) C) and E)

Question 16

Figure 7.1
-Carbon skeletons for amino acid biosynthesis are supplied by intermediates of the citric acid cycle. Which intermediate could directly supply the carbon skeleton for synthesis of a five-carbon amino acid (see Figure 7.1) ?

Accepted Answer

A)   succinate
B)   malate
C)   citrate
D)   α-ketoglutarate
E)   isocitrateF) C) and D)
G) B) and E)

Question 17

The ATP made during fermentation is generated by which of the following?

Accepted Answer

A)   the electron transport chain
B)   substrate-level phosphorylation
C)   chemiosmosis
D)   oxidative phosphorylation
E)   aerobic respirationF) None of the above
G) A) and B)

Question 18

Why are carbohydrates and fats considered high-energy foods?

Accepted Answer

A)   They have a lot of oxygen atoms.
B)   They have few nitrogen atoms.
C)   They have a large number of electrons associated with hydrogen.
D)   They have a lot of carbon atoms bound together by single covalent bonds.
E)   They are easily reduced.F) A) and D)
G) None of the above

Question 19

The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the

Accepted Answer

A)   oxidation of glucose and other organic compounds.
B)   flow of electrons down the electron transport chain.
C)   H+ concentration gradient across the membrane holding ATP synthase.
D)   transfer of phosphate to ADP.E) None of the above
F) A) and D)

Question 20

What fraction of the carbon dioxide exhaled by animals is generated by the oxidation of pyruvate to acetyl CoA, if glucose is the sole energy source?

Accepted Answer

A)   1/6
B)   1/3
C)   1/2
D)   2/3
E)   all of itF) A) and E)
G) A) and B)

Exam 7: Cellular Respiration and Fermentation

Figure 7.1 -Carbon skeletons for amino acid biosynthesis are supplied by intermediates of the citric acid cycle. Which intermediate could directly supply the carbon skeleton for synthesis of a five-carbon amino acid (see Figure 7.1) ?

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The complete oxidation of glucose (C₆H₁₂O₆) to carbon dioxide and water in aerobic respiration consumes how many molecules of oxygen (O₂) ?

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Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions of glycolysis?

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Figure 7.2 -What happens at the end of the chain in Figure 7.2?

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Which kind of metabolic poison would most directly interfere with glycolysis?

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What fraction of the carbon dioxide exhaled by animals is generated by the oxidation of pyruvate to acetyl CoA, if glucose is the sole energy source?

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Yeast cells grown anaerobically can obtain energy by fermentation, which results in the production of

Correct AnswerverifiedShow Answer

Which of the following produces the most ATP when glucose (C₆H₁₂O₆) is completely oxidized to carbon dioxide (CO₂) and water?

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Which metabolic pathway requires a proton gradient?

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When an electron is transferred to a more electronegative atom

Correct AnswerverifiedShow Answer

The ATP made during fermentation is generated by which of the following?

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When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?

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In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve?

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Figure 7.2 -Which of the protein complexes labeled with Roman numerals in Figure 7.2 will transfer electrons to O₂?

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When an individual is exercising heavily and the muscle becomes oxygen-deprived, muscle cells convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells?

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The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the

Correct AnswerverifiedShow Answer

In alcohol fermentation, NAD+ is regenerated from NADH by

Correct AnswerverifiedShow Answer

Why are carbohydrates and fats considered high-energy foods?

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Which catabolic processes may have been used by cells on ancient Earth before free oxygen became available?

Correct AnswerverifiedShow Answer

When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is

Correct AnswerverifiedShow Answer

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