Question 1

If a cell produces on average 30 ATP molecules for each molecule of glucose that is completely oxidized to carbon dioxide and water, how many ATP molecules on average can the cell synthesize for each molecule of pyruvate oxidized to carbon dioxide and water?

Accepted Answer

A)   8
B)   12.5
C)   14
D)   25

Question 2

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 ATPsynthase
D)   transfer of phosphate to ADP

Question 3

Which of the following types 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+

Question 4

Which of the following sequences describes the path by which electrons move from high-energy to lower-energy molecules in aerobic respiration?

Accepted Answer

A)   glucose → NADH → electron transport chain → oxygen
B)   glucose → pyruvate → ATP → oxygen
C)   glucose → pyruvate → electron transport chain → NADH → ATP
D)   food → glycolysis → citric acid cycle → NADH → ATP

Question 5

Which of the following is one of the molecules formed by the removal of a carboxyl group (as CO2)  from a molecule of pyruvate?

Accepted Answer

A)   ATP
B)   acetyl CoA
C)   citrate
D)   water

Question 6

Exposing inner mitochondrial membranes to ultrasonic vibrations will fragment the membranes and pieces will reseal to form small vesicles that contain the intermembrane space. These vesicles can transfer electrons from NADH to oxygen and synthesize ATP. Which of the following statements best describes what will happen to the vesicles when NADH is added?

Accepted Answer

A)   The inside of the vesicles will become acidic.
B)   The inside of the vesicles will become alkaline.
C)   ATP will be produced from ADP and  i in the interior of the vesicle.
D)   Protons will be pumped out of the interior of the vesicle to the exterior using energy from ATP hydrolysis.

Question 7

The citric acid cycle.
If pyruvate oxidation is blocked, what is the most likely effect on the levels of oxaloacetate and citrate in the citric acid cycle shown in the accompanying figure?

Accepted Answer

A)   Oxaloacetate will decrease and citrate will accumulate.
B)   Oxaloacetate will accumulate and citrate will decrease.
C)   Both oxaloacetate and citrate will decrease.
D)   Both oxaloacetate and citrate will accumulate.

Question 8

In mitochondria, exergonic redox reactions ________.

Accepted Answer

A)   are the source of energy driving prokaryotic ATP synthesis
B)   provide the energy that establishes the proton gradient
C)   reduce carbon atoms to carbon dioxide
D)   are coupled via phosphorylated intermediates to endergonic processes

Question 9

Which of the following reactions produces the majority of the CO2 released by the complete oxidation of glucose?

Accepted Answer

A)   glycolysis
B)   electron transport
C)   oxidation of pyruvate to acetyl-CoA
D)   the citric acid cycle

Question 10

If the proteins of the electron transport chain were labeled with a fluorescent tag, the fluorescence observed by microscopy will be localized to which of the following regions of the mitochondria?

Accepted Answer

A)   outer membrane
B)   inner membrane
C)   intermembrane space
D)   matrix

Question 11

Which of the summary statements below best describes the results of the following reaction?
C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy

Accepted Answer

A)   C6H12O6 is oxidized and O2 is reduced.
B)   O2 is oxidized and H2O is reduced.
C)   CO2 is reduced and O2 is oxidized.
D)   O2 is reduced and CO2 is oxidized. A

Question 12

The enzyme phosphofructokinase (PFK)  catalyzes a key step in glycolysis. About 10% of Springer spaniels suffer from canine PFK deficiency. Dogs affected with this disorder most likely display which of the following symptoms?

Accepted Answer

A)   They die as embryos.
B)   They constantly have low blood sugar.
C)   They are lethargic and readily tire from exercise.
D)   They carry out elevated levels of oxidative phosphorylation.

Question 13

In chemiosmosis, the most direct source of energy used to convert ADP +  i to ATP is energy released ________.

Accepted Answer

A)   as electrons flow through the electron transport chain
B)   from substrate-level phosphorylation
C)   from movement of protons through ATP synthase, down their electrochemical gradient
D)   as electrons are transported across the inner mitochondrial membrane

Question 14

The enzyme phosphofructokinase (PFK)  catalyzes a key step in glycolysis and is inhibited by high levels of which of the following molecules?

Accepted Answer

A)   glucose and NAD+
B)   AMP and ATP
C)   ATP and citrate
D)   citrate and CO2

Question 15

What is the oxidizing agent in the following reaction?
Pyruvate + NADH + H+ → Lactate + NAD+

Accepted Answer

A)   oxygen
B)   NADH
C)   lactate
D)   pyruvate D

Question 16

Which of the following statements best describes the primary role played by oxygen in cellular respiration?

Accepted Answer

A)   It yields energy in the form of ATP as it is passed down the electron transport chain.
B)   It oxidizes glucose to form two molecules of pyruvate.
C)   It serves as an acceptor for carbon, forming CO2 in the citric acid cycle.
D)   It serves as the final acceptor for electrons from the electron transport chain.

Question 17

New biosensors, applied like a temporary tattoo to the skin, can alert endurance athletes that they are about to "hit the wall" and will find it difficult to continue exercising. These biosensors monitor lactate present in sweat during strenuous exercise. Which of the statements below best explains the use of lactate as an indicator of exercise capacity?

Accepted Answer

A)   During aerobic respiration, muscle cells cannot produce enough lactate to fuel muscle cell contractions, and muscles begin to cramp, thus athletic performance suffers.
B)   During anaerobic respiration, lactate levels increase when muscles cells need more energy; however, muscles cells eventually fatigue, thus athletes should modify their activities to increase aerobic respiration.
C)   During aerobic respiration, muscles cells produce too much lactate, which causes a rise in the pH of the muscle cells, thus athletes must consume increased amounts of sports drinks, high in electrolytes, to buffer the pH.
D)   During anaerobic respiration, muscle cells receive too little oxygen and begin to convert lactate to pyruvate (pyruvic acid) , thus athletes experience cramping and fatigue.

Question 18

Which of the following statements best explains why carbohydrates and fats may be considered high-energy foods?

Accepted Answer

A)   They contain many protons associated with oxygen atoms.
B)   They contain no low-energy nitrogen atoms.
C)   They contain many electrons associated with hydrogen atoms.
D)   They are strong oxidizing molecules.

Question 19

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

Accepted Answer

A)   0%
B)   2%
C)   38%
D)   100%

Question 20

Which of the following statements best describes a characteristic of NAD+?

Accepted Answer

A)   NAD+ is reduced to NADH in glycolysis, pyruvate oxidation, and the citric acid cycle.
B)   NAD+ stores more chemical energy than NADH.
C)   NAD+ may donate electrons for use in oxidative phosphorylation.
D)   NAD+ is oxidized in glycolysis to produce ATP. A

Exam 10: Cell Respiration

If a cell produces on average 30 ATP molecules for each molecule of glucose that is completely oxidized to carbon dioxide and water, how many ATP molecules on average can the cell synthesize for each molecule of pyruvate oxidized to carbon dioxide and water?

Correct Answer
verified

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

Correct Answer
verified

Which of the following types of metabolic poison would most directly interfere with glycolysis?

Correct Answer
verified

Which of the following sequences describes the path by which electrons move from high-energy to lower-energy molecules in aerobic respiration?

Correct Answer
verified

Which of the following is one of the molecules formed by the removal of a carboxyl group (as CO₂) from a molecule of pyruvate?

Correct Answer
verified

Correct Answer
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The citric acid cycle. If pyruvate oxidation is blocked, what is the most likely effect on the levels of oxaloacetate and citrate in the citric acid cycle shown in the accompanying figure?

Correct Answer
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In mitochondria, exergonic redox reactions ________.

Correct Answer
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Which of the following reactions produces the majority of the CO₂ released by the complete oxidation of glucose?

Correct Answer
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If the proteins of the electron transport chain were labeled with a fluorescent tag, the fluorescence observed by microscopy will be localized to which of the following regions of the mitochondria?

Correct Answer
verified

Which of the summary statements below best describes the results of the following reaction? C6H12O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy

Correct Answer
verified
A

The enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis. About 10% of Springer spaniels suffer from canine PFK deficiency. Dogs affected with this disorder most likely display which of the following symptoms?

Correct Answer
verified

In chemiosmosis, the most direct source of energy used to convert ADP + i to ATP is energy released ________.

Correct Answer
verified

The enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis and is inhibited by high levels of which of the following molecules?

Correct Answer
verified

What is the oxidizing agent in the following reaction? Pyruvate + NADH + H+ → Lactate + NAD+

Correct Answer
verified
D

Which of the following statements best describes the primary role played by oxygen in cellular respiration?

Correct Answer
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Correct Answer
verified

Which of the following statements best explains why carbohydrates and fats may be considered high-energy foods?

Correct Answer
verified

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

Correct Answer
verified

Which of the following statements best describes a characteristic of NAD+?

Correct Answer
verified
A

Exam 10: Cell Respiration

If a cell produces on average 30 ATP molecules for each molecule of glucose that is completely oxidized to carbon dioxide and water, how many ATP molecules on average can the cell synthesize for each molecule of pyruvate oxidized to carbon dioxide and water?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following types of metabolic poison would most directly interfere with glycolysis?

Correct AnswerverifiedShow Answer

Which of the following sequences describes the path by which electrons move from high-energy to lower-energy molecules in aerobic respiration?

Correct AnswerverifiedShow Answer

Which of the following is one of the molecules formed by the removal of a carboxyl group (as CO2) from a molecule of pyruvate?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The citric acid cycle. If pyruvate oxidation is blocked, what is the most likely effect on the levels of oxaloacetate and citrate in the citric acid cycle shown in the accompanying figure?

Correct AnswerverifiedShow Answer

In mitochondria, exergonic redox reactions ________.

Correct AnswerverifiedShow Answer

Which of the following reactions produces the majority of the CO2 released by the complete oxidation of glucose?

Correct AnswerverifiedShow Answer

If the proteins of the electron transport chain were labeled with a fluorescent tag, the fluorescence observed by microscopy will be localized to which of the following regions of the mitochondria?

Correct AnswerverifiedShow Answer

Which of the summary statements below best describes the results of the following reaction? C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy

Correct AnswerverifiedA

The enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis. About 10% of Springer spaniels suffer from canine PFK deficiency. Dogs affected with this disorder most likely display which of the following symptoms?

Correct AnswerverifiedShow Answer

In chemiosmosis, the most direct source of energy used to convert ADP + i to ATP is energy released ________.

Correct AnswerverifiedShow Answer

The enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis and is inhibited by high levels of which of the following molecules?

Correct AnswerverifiedShow Answer

What is the oxidizing agent in the following reaction? Pyruvate + NADH + H+ → Lactate + NAD+

Correct AnswerverifiedD

Which of the following statements best describes the primary role played by oxygen in cellular respiration?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following statements best explains why carbohydrates and fats may be considered high-energy foods?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following statements best describes a characteristic of NAD+?

Correct AnswerverifiedA

Correct Answer
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Which of the following is one of the molecules formed by the removal of a carboxyl group (as CO₂) from a molecule of pyruvate?

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Which of the following reactions produces the majority of the CO₂ released by the complete oxidation of glucose?

Correct Answer
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Correct Answer
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Which of the summary statements below best describes the results of the following reaction? C6H12O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy

Correct Answer
verified
A

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D

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A