Question 1

The oxidizing agent at the end of the electron transport chain is

Accepted Answer

A)  O2. 
B)  NAD+. 
C)  ATP. 
D)  FAD. 
E)  ubiquinone. 
A)  O2. 
B)  NAD+. 
C)  ATP. 
D)  FAD. 
E)  ubiquinone.

Question 2

The mitochondrial electron transport chain

Accepted Answer

A)  is the site of most of the reactions of the citric acid cycle. 
B)  synthesizes ATP. 
C)  pumps protons into the mitochondrial matrix during electron transport. 
D)  oxidizes the intermediate electron carriers, NADH and FADH2. 
E)  oxidizes water to O2 and 2 H+. 
A)  is the site of most of the reactions of the citric acid cycle. 
B)  synthesizes ATP. 
C)  pumps protons into the mitochondrial matrix during electron transport. 
D)  oxidizes the intermediate electron carriers, NADH and FADH2. 
E)  oxidizes water to O2 and 2 H+.

Question 3

If a cell has an abundant supply of ATP, acetyl CoA may be used

Accepted Answer

A)  to enhance fermentation. 
B)  to enhance oxidative metabolism. 
C)  for fatty acid synthesis. 
D)  to convert glucose to glycogen. 
E)  None of the above 
A)  to enhance fermentation. 
B)  to enhance oxidative metabolism. 
C)  for fatty acid synthesis. 
D)  to convert glucose to glycogen. 
E)  None of the above

Question 4

During alcoholic fermentation, NAD+ is regenerated by the reduction of acetaldehyde to _______.

Accepted Answer

Question 5

How does the reduction of pyruvate to lactic acid during fermentation allow glycolysis to continue in the absence of oxygen?

Accepted Answer

A)  Water is formed during this reaction. 
B)  This reaction is a kinase reaction. 
C)  This reaction is coupled to the oxidation of NADH to NAD+. 
D)  This reaction is coupled to the formation of ATP. 
E)  This reaction is coupled to the reduction of NAD+ to NADH. 
A)  Water is formed during this reaction. 
B)  This reaction is a kinase reaction. 
C)  This reaction is coupled to the oxidation of NADH to NAD+. 
D)  This reaction is coupled to the formation of ATP. 
E)  This reaction is coupled to the reduction of NAD+ to NADH.

Question 6

For glucose to be used as an energy source, it is necessary that

Accepted Answer

A)  glucose be formed from fructose. 
B)  glucose phosphate be formed from fructose phosphate. 
C)  glucose be degraded to carbon dioxide. 
D)  two ATP molecules be invested in the system. 
E)  None of the above 
A)  glucose be formed from fructose. 
B)  glucose phosphate be formed from fructose phosphate. 
C)  glucose be degraded to carbon dioxide. 
D)  two ATP molecules be invested in the system. 
E)  None of the above

Question 7

Compared with fermentation, the aerobic pathways of glucose metabolism produce

Accepted Answer

A)  more ATP. 
B)  pyruvate. 
C)  fewer protons for pumping in the mitochondria. 
D)  less CO2. 
E)  more oxidized coenzymes. 
A)  more ATP. 
B)  pyruvate. 
C)  fewer protons for pumping in the mitochondria. 
D)  less CO2. 
E)  more oxidized coenzymes.

Question 8

The conversion of glucose to lactic acid is a form of _______.

Accepted Answer

The answer of The conversion of glucose to lactic acid...

Question 9

ATP is used to drive the first five reactions of glycolysis because

Accepted Answer

A)  nonspontaneous reactions are exergonic. 
B)  the breakdown of ATP to ADP is exergonic. 
C)  the breakdown of ATP to ADP is endergonic. 
D)  when ATP is broken down to ADP, Pi is released. 
E)  ADP possesses more free energy than ATP does. 
A)  nonspontaneous reactions are exergonic. 
B)  the breakdown of ATP to ADP is exergonic. 
C)  the breakdown of ATP to ADP is endergonic. 
D)  when ATP is broken down to ADP, Pi is released. 
E)  ADP possesses more free energy than ATP does.

Question 10

Which one of the following reactions is not an oxidation-reduction reaction?

Accepted Answer

A)  NADH + 1/2O2 + H+ $\leftrightarrow$ NAD+ + H2O 
B)  R-CH=CH-CH3 + H2O $\leftrightarrow$ RCH2-CH(OH)-CH3 
C)  FAD + H2O $\leftrightarrow$ FADH2 + 1/2O2 
D)  NADH + acetaldehyde $\leftrightarrow$ NAD+ + ethanol 
E)  AH2 + B $\leftrightarrow$ A + BH2 
A)  NADH + 1/2O2 + H+ $\leftrightarrow$ NAD+ + H2O 
B)  R-CH=CH-CH3 + H2O $\leftrightarrow$ RCH2-CH(OH)-CH3 
C)  FAD + H2O $\leftrightarrow$ FADH2 + 1/2O2 
D)  NADH + acetaldehyde $\leftrightarrow$ NAD+ + ethanol 
E)  AH2 + B $\leftrightarrow$ A + BH2

Question 11

Which of the following is produced during the citric acid cycle?

Accepted Answer

A)  FAD 
B)  Pyruvate 
C)  Reduced electron carriers 
D)  Lactic acid 
E)  Water 
A)  FAD 
B)  Pyruvate 
C)  Reduced electron carriers 
D)  Lactic acid 
E)  Water

Question 12

During the energy-priming portion of glycolysis, the phosphates from ATP molecules are

Accepted Answer

A)  added to the first and sixth carbons. 
B)  added to the second and fourth carbons. 
C)  wasted, as an energy investment. 
D)  used to make pyruvate. 
E)  used to make lactate. 
A)  added to the first and sixth carbons. 
B)  added to the second and fourth carbons. 
C)  wasted, as an energy investment. 
D)  used to make pyruvate. 
E)  used to make lactate.

Question 13

The fate of acetyl CoA differs according to how much ATP is present in the cell. Explain what happens to acetyl CoA when ATP is limited, and compare that to what happens when acetyl CoA is abundant. How do these processes help regulate metabolism?

Accepted Answer

If ATP is limited, acetyl CoA enters the

Question 14

The hydrogen ion gradient is maintained by

Accepted Answer

A)  electron transport and proton pumping. 
B)  the splitting of water. 
C)  the ionization of glucose. 
D)  ATP synthase. 
E)  acetyl CoA. 
A)  electron transport and proton pumping. 
B)  the splitting of water. 
C)  the ionization of glucose. 
D)  ATP synthase. 
E)  acetyl CoA.

Exam 9: Pathways That Harvest Chemical Energy

The oxidizing agent at the end of the electron transport chain is

The mitochondrial electron transport chain

If a cell has an abundant supply of ATP, acetyl CoA may be used

During alcoholic fermentation, NAD+ is regenerated by the reduction of acetaldehyde to _______.

How does the reduction of pyruvate to lactic acid during fermentation allow glycolysis to continue in the absence of oxygen?

For glucose to be used as an energy source, it is necessary that

Compared with fermentation, the aerobic pathways of glucose metabolism produce

The conversion of glucose to lactic acid is a form of _______.

ATP is used to drive the first five reactions of glycolysis because

Which one of the following reactions is not an oxidation-reduction reaction?

Which of the following is produced during the citric acid cycle?

During the energy-priming portion of glycolysis, the phosphates from ATP molecules are

The fate of acetyl CoA differs according to how much ATP is present in the cell. Explain what happens to acetyl CoA when ATP is limited, and compare that to what happens when acetyl CoA is abundant. How do these processes help regulate metabolism?

The hydrogen ion gradient is maintained by

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During alcoholic fermentation, NAD⁺ is regenerated by the reduction of acetaldehyde to _______.