Question 1

The reduction of pyruvate to lactic acid during fermentation allows glycolysis to continue in the absence of O2 because this reaction

Accepted Answer

A)  produces H2O. 
B)  is a kinase reaction. 
C)  is coupled to the oxidation of NADH to NAD+. 
D)  is coupled to the formation of ATP. 
E)  is coupled to the reduction of NAD+ to NADH. 
A)  produces H2O. 
B)  is a kinase reaction. 
C)  is coupled to the oxidation of NADH to NAD+. 
D)  is coupled to the formation of ATP. 
E)  is coupled to the reduction of NAD+ to NADH.

Question 2

Yeasts are single-celled organisms that can grow in aerobic or anaerobic conditions.Explain how and why a yeast population growing in an aerobic environment would be affected if the environment suddenly became an anaerobic one.In your discussion, address energy, growth rate, and gene expression.

Accepted Answer

A yeast population suddenly moved from a

Question 3

A research scientist divides mouse liver cells growing in culture into two groups.One group (fed group) is supplied with a complete set of nutrients and a constant supply of glucose at the level normally supplied by the blood in the whole animal.A second group (fasted group) is supplied with the same medium without glucose.The fasted cells are predicted to increase _______ breakdown, while the fed cells are predicted to show no change in this pathway.

Accepted Answer

The answer of A research scientist divides mouse liver cells...

Question 4

A suspension of yeast supplied with glucose as its source of energy was transferred from an aerobic environment to an anaerobic one.Which result would you predict for the rate of glucose utilization and the rate of ethanol production after the transfer? Assume that the yeast must expend the same amount of energy to survive in both environments.

Accepted Answer

A)  Glucose usage would decrease, and ethanol production would increase. 
B)  Glucose usage would increase, and ethanol production would decrease. 
C)  Both glucose usage and ethanol production would increase. 
D)  Neither glucose usage nor ethanol production would change. 
E)  Glucose usage would not change, and ethanol production would increase. 
A)  Glucose usage would decrease, and ethanol production would increase. 
B)  Glucose usage would increase, and ethanol production would decrease. 
C)  Both glucose usage and ethanol production would increase. 
D)  Neither glucose usage nor ethanol production would change. 
E)  Glucose usage would not change, and ethanol production would increase.

Question 5

Refer to the diagram below.   The diagram illustrates how the glycolytic pathway can be separated into two groups of steps-initial steps and later steps.Explain how the initial steps in the glycolytic pathway differ from later steps.In your discussion, address the types of reactions taking place and how energy is involved.

Accepted Answer

The initial steps of glycolysis are ende

Question 6

Which of the following statements can be used as evidence that living cells follow the same basic principles of chemistry that nonliving systems follow?

Accepted Answer

A)  Cells use three catabolic processes to harvest energy in the chemical bonds of glucose: glycolysis, cellular respiration, and fermentation. 
B)  Anaerobic oxidation of glucose is incomplete, since oxidation does not proceed completely to carbon dioxide and water, but stops at an intermediate end product. 
C)  Each step in the oxidation of glucose in a cell is catalyzed by a different enzyme. 
D)  One mole of glucose burned in a dish releases 686 kcal of heat energy, while a group of cells oxidizing the same quantity of glucose releases the same quantity of energy in a different form. 
E)  In a cell, different steps in the complete oxidation of glucose are carried out in different cellular compartments. 
A)  Cells use three catabolic processes to harvest energy in the chemical bonds of glucose: glycolysis, cellular respiration, and fermentation. 
B)  Anaerobic oxidation of glucose is incomplete, since oxidation does not proceed completely to carbon dioxide and water, but stops at an intermediate end product. 
C)  Each step in the oxidation of glucose in a cell is catalyzed by a different enzyme. 
D)  One mole of glucose burned in a dish releases 686 kcal of heat energy, while a group of cells oxidizing the same quantity of glucose releases the same quantity of energy in a different form. 
E)  In a cell, different steps in the complete oxidation of glucose are carried out in different cellular compartments.

Question 7

Which product of glycolysis is transported across the mitochondrial membrane, where it is converted to the molecule that enters the citric acid cycle?

Accepted Answer

A)  Glucose 
B)  Pyruvate 
C)  Acetyl CoA 
D)  NADH + H+ 
E)  ATP synthase 
A)  Glucose 
B)  Pyruvate 
C)  Acetyl CoA 
D)  NADH + H+ 
E)  ATP synthase

Question 8

In an experiment, the F1 portion of the ATP synthase was labeled with a fluorescently labeled microfilament and attached to a glass slide.The rotation of the ATP synthase was observed when ATP was added.When ATP plus oligomycin was added to the slide, the rotation continued even though oligomycin can inhibit ATP hydrolysis in mitochondrial inner membrane vesicles containing ATP synthase (F1-F0).Based on your knowledge of ATP synthase, which hypothesis is supported by these observations?

Accepted Answer

A)  Oligomycin binds to ATP synthase (F1) and interferes with the rotation. 
B)  Oligomycin binds to ATP synthase (F1) on the slide because the binding site is not blocked. 
C)  Oligomycin binds the ATP synthase (F1-F0) only when it is attached to the membrane. 
D)  Oligomycin binds to the slide. 
E)  Oligomycin cannot bind to the ATP synthase (F1-F0) when it is attached to the membrane. 
A)  Oligomycin binds to ATP synthase (F1) and interferes with the rotation. 
B)  Oligomycin binds to ATP synthase (F1) on the slide because the binding site is not blocked. 
C)  Oligomycin binds the ATP synthase (F1-F0) only when it is attached to the membrane. 
D)  Oligomycin binds to the slide. 
E)  Oligomycin cannot bind to the ATP synthase (F1-F0) when it is attached to the membrane.

Question 9

Which describes how the components of the respiratory chain are ordered?

Accepted Answer

A)  From large to small mass 
B)  From high to low reduction potential relative to oxygen 
C)  From high to low ability to pump protons across the inner membrane 
D)  From low to high ability to pass electrons to oxygen 
E)  From low to high free energy relative to oxygen 
A)  From large to small mass 
B)  From high to low reduction potential relative to oxygen 
C)  From high to low ability to pump protons across the inner membrane 
D)  From low to high ability to pass electrons to oxygen 
E)  From low to high free energy relative to oxygen

Question 10

The formation of ethanol from pyruvate is an example of

Accepted Answer

A)  an irreversible reaction. 
B)  a fermentation process that takes place in the absence of O2. 
C)  the production of extra energy from glycolysis. 
D)  cellular respiration. 
E)  a high-energy-yielding process. 
A)  an irreversible reaction. 
B)  a fermentation process that takes place in the absence of O2. 
C)  the production of extra energy from glycolysis. 
D)  cellular respiration. 
E)  a high-energy-yielding process.

Question 11

Refer to the figure below.   Which statement correctly describes this oxidation-reduction reaction?

Accepted Answer

A)  Malate is reduced to oxaloacetate, and NAD+ is oxidized to NADH. 
B)  Malate is reduced to NADH, and oxaloacetate is oxidized to NAD+. 
C)  Malate is oxidized to oxaloacetate, and NAD+ is reduced to NADH. 
D)  Malate is oxidized to NADH, and oxaloacetate is reduced to NAD+. 
E)  Malate is oxidized to NAD+, and oxaloacetate is reduced to NADH. 
A)  Malate is reduced to oxaloacetate, and NAD+ is oxidized to NADH. 
B)  Malate is reduced to NADH, and oxaloacetate is oxidized to NAD+. 
C)  Malate is oxidized to oxaloacetate, and NAD+ is reduced to NADH. 
D)  Malate is oxidized to NADH, and oxaloacetate is reduced to NAD+. 
E)  Malate is oxidized to NAD+, and oxaloacetate is reduced to NADH.

Question 12

The following reaction summarizes the overall chemical change that takes place as the result of electrons transferred along the respiratory chain.   The formation of ATP from ADP and Pi requires the input of 7.3 kcal/mol.The respiratory chain can efficiently convert the majority of the free energy released from electrons to the chemical energy of phosphate bonds in ATP molecules, without a lot of wasted energy given off as heat.Which characteristic of the respiratory chain explains how this is possible?

Accepted Answer

A)  The number of components in the respiratory chain 
B)  The sizes of the components of the respiratory chain 
C)  The protein nature of many of the components in the respiratory chain 
D)  The location of the components in the inner mitochondrial membrane 
E)  The identity of the final electron acceptor at the end of the respiratory chain 
A)  The number of components in the respiratory chain 
B)  The sizes of the components of the respiratory chain 
C)  The protein nature of many of the components in the respiratory chain 
D)  The location of the components in the inner mitochondrial membrane 
E)  The identity of the final electron acceptor at the end of the respiratory chain

Question 13

Electrons are shuttled from glycolysis and the citric acid cycle to the respiratory chain via

Accepted Answer

A)  ATP. 
B)  FADH2 only. 
C)  FADH2 and NADH. 
D)  NADH only. 
E)  GTP. 
A)  ATP. 
B)  FADH2 only. 
C)  FADH2 and NADH. 
D)  NADH only. 
E)  GTP.

Question 14

Construct a graph to show how the free energy of an electron changes as it is passed along the respiratory chain.

Accepted Answer

Figure 9.7 illustrates how an electron b

Question 15

The end products of glycolysis are

Accepted Answer

A)  pyruvate, ATP, and CO2. 
B)  pyruvate, ATP, and NAD+. 
C)  pyruvate, ATP, and NADH. 
D)  acetyl CoA, ATP, and NAD+. 
E)  acetyl CoA, ATP, and NADH. 
A)  pyruvate, ATP, and CO2. 
B)  pyruvate, ATP, and NAD+. 
C)  pyruvate, ATP, and NADH. 
D)  acetyl CoA, ATP, and NAD+. 
E)  acetyl CoA, ATP, and NADH.

Question 16

When a person runs for an extended period of time, the main source of glucose for muscle cells comes from the breakdown of glycogen in the

Accepted Answer

A)  muscle. 
B)  liver. 
C)  electron transport chain. 
D)  lungs. 
E)  heart. 
A)  muscle. 
B)  liver. 
C)  electron transport chain. 
D)  lungs. 
E)  heart.

Question 17

Allosteric regulation of an enzyme means that the enzyme may

Accepted Answer

A)  increase its activity as the result of phosphorylation. 
B)  increase its activity as the result of dephosphorylation. 
C)  decrease its activity in the presence of a product of the same or a different pathway. 
D)  decrease its activity as substrate of the enzyme decreases in concentration. 
E)  increase its activity as more enzyme is synthesized via translation of increased mRNA encoding the enzyme. 
A)  increase its activity as the result of phosphorylation. 
B)  increase its activity as the result of dephosphorylation. 
C)  decrease its activity in the presence of a product of the same or a different pathway. 
D)  decrease its activity as substrate of the enzyme decreases in concentration. 
E)  increase its activity as more enzyme is synthesized via translation of increased mRNA encoding the enzyme.

Question 18

Refer to the diagram below, showing electron transport and ATP synthesis.When pure reduced cytochrome c is added to isolated mitochondria in a solution containing ADP, Pi, O2, and antimycin A (a mitochondria complex II inhibitor), the cytochrome c becomes oxidized and ATP is formed.   Which sequence represents the probable flow of electrons in this system?

Accepted Answer

A)  NADH-Q reductase F1F1F1S1F1F1F10 cytochrome c F1F1F1S1F1F1F10 complex IV F1F1F1S1F1F1F10 O2 
B)  Cytochrome c F1F1F1S1F1F1F10 O2 F1F1F1S1F1F1F10 complex IV 
C)  Complex IV F1F1F1S1F1F1F10 cytochrome c F1F1F1S1F1F1F10 O2 
D)  Cytochrome c F1F1F1S1F1F1F10 complex IV F1F1F1S1F1F1F10 O2 
E)  Cytochrome c F1F1F1S1F1F1F10 NADH-Q reductase F1F1F1S1F1F1F10 complex IV F1F1F1S1F1F1F10 O2 
A)  NADH-Q reductase F1F1F1S1F1F1F10 cytochrome c F1F1F1S1F1F1F10 complex IV F1F1F1S1F1F1F10 O2 
B)  Cytochrome c F1F1F1S1F1F1F10 O2 F1F1F1S1F1F1F10 complex IV 
C)  Complex IV F1F1F1S1F1F1F10 cytochrome c F1F1F1S1F1F1F10 O2 
D)  Cytochrome c F1F1F1S1F1F1F10 complex IV F1F1F1S1F1F1F10 O2 
E)  Cytochrome c F1F1F1S1F1F1F10 NADH-Q reductase F1F1F1S1F1F1F10 complex IV F1F1F1S1F1F1F10 O2

Question 19

The citric acid cycle produces

Accepted Answer

A)  ethanol. 
B)  pyruvate. 
C)  H2O. 
D)  lactic acid. 
E)  NADH and FADH2. 
A)  ethanol. 
B)  pyruvate. 
C)  H2O. 
D)  lactic acid. 
E)  NADH and FADH2.

Question 20

Which analogy best describes the mechanism of ATP synthase?

Accepted Answer

A)  A ball bouncing down a stairway bumps into a cart and causes it to roll forward. 
B)  Water flowing across a waterwheel makes the wheel turn, which causes a milling grindstone to turn. 
C)  A rubber band stores more and more potential energy as it is continually twisted in one direction. 
D)  A snowball pushed down a hill becomes larger and larger as it picks up snow as it rolls. 
E)  A bucket of water positioned on top of a half-opened door spills its load as the door is pushed open. 
A)  A ball bouncing down a stairway bumps into a cart and causes it to roll forward. 
B)  Water flowing across a waterwheel makes the wheel turn, which causes a milling grindstone to turn. 
C)  A rubber band stores more and more potential energy as it is continually twisted in one direction. 
D)  A snowball pushed down a hill becomes larger and larger as it picks up snow as it rolls. 
E)  A bucket of water positioned on top of a half-opened door spills its load as the door is pushed open.

Exam 9: Pathways That Harvest Chemical Energy

The reduction of pyruvate to lactic acid during fermentation allows glycolysis to continue in the absence of O2 because this reaction

Yeasts are single-celled organisms that can grow in aerobic or anaerobic conditions.Explain how and why a yeast population growing in an aerobic environment would be affected if the environment suddenly became an anaerobic one.In your discussion, address energy, growth rate, and gene expression.

Which of the following statements can be used as evidence that living cells follow the same basic principles of chemistry that nonliving systems follow?

Which product of glycolysis is transported across the mitochondrial membrane, where it is converted to the molecule that enters the citric acid cycle?

Which describes how the components of the respiratory chain are ordered?

The formation of ethanol from pyruvate is an example of

Refer to the figure below. Which statement correctly describes this oxidation-reduction reaction?

Electrons are shuttled from glycolysis and the citric acid cycle to the respiratory chain via

Construct a graph to show how the free energy of an electron changes as it is passed along the respiratory chain.

The end products of glycolysis are

When a person runs for an extended period of time, the main source of glucose for muscle cells comes from the breakdown of glycogen in the

Allosteric regulation of an enzyme means that the enzyme may

The citric acid cycle produces

Which analogy best describes the mechanism of ATP synthase?

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The reduction of pyruvate to lactic acid during fermentation allows glycolysis to continue in the absence of O₂ because this reaction