Question 1

The fate of pyruvate produced during glycolysis depends primarily on the availability of

Accepted Answer

A)   NAD+ to keep the pathway going.
B)   molecular oxygen.
C)   ADP for conversion to ATP.
D)   coenzyme A for further metabolism of pyruvate.
E)   phosphoric acid for the synthesis of ATP.F) All of the above
G) C) and D)

Question 2

The phosphorylation of fructose 6-phosphate to fructose-1,6-bisphosphate is the committed step in glycolysis because

Accepted Answer

A)   it is the rate-limiting step.
B)   it is the most strongly exergonic step in the pathway.
C)   fructose 1,6-bisphosphate can undergo no other reactions than those of glycolysis.
D)   two phosphate groups are involved.E) A) and C)
F) A) and D)

Question 3

During glycolysis, ATP is synthesized from ADP and a phosphate group transferred from an acid anhydride.

Accepted Answer

A) True 
 B)False

Question 4

During anaerobic metabolism in red blood cells, the carbons of glucose end up in

Accepted Answer

A)   CO2.
B)   ethanol.
C)   lactic acid.
D)   both CO2 and ethanol.
E)   all of the above.F) A) and D)
G) B) and D)

Question 5

The equilibrium for isomerization of dihydroxyacetone phosphate to glyceraldehyde-3-phosphate is favored because

Accepted Answer

A)   the standard free energy is negative
B)   glyceraldehyde-3-phosphate is being continuously drained off for the subsequent reaction in the glycolytic pathway
C)   the value of the equilibrium constant favors the reaction
D)   it is driven by the hydrolysis of ATPE) A) and C)
F) A) and B)

Question 6

During anaerobic metabolism in yeast, the carbons of glucose end up in

Accepted Answer

A)   CO2.
B)   ethanol.
C)   lactic acid.
D)   both CO2 and ethanol.
E)   all of theseF) D) and E)
G) A) and B)

Question 7

Which of the following enzymes of glycolysis is not involved in regulation of the pathway?

Accepted Answer

A)   Hexokinase
B)   Phosphofructokinase
C)   Aldolase
D)   Pyruvate kinase
E)   All of these proteins regulate glycolysis.F) A) and B)
G) C) and D)

Question 8

Consider the following information: phosphoenolpyruvate → pyruvate
ΔG°' = −61.9 kJ/mol
ADP + Pi → ATP
ΔG°' = +30.5 kJ/mol
How many molecules of ATP might theoretically have been produced when coupled to the conversion of one molecule phosphoenolpyruvate to pyruvate?

Accepted Answer

A)   1
B)   2
C)   3
D)   4E) A) and B)
F) C) and D)

Question 9

How many steps in glycolysis have ATP as a substrate or product?

Accepted Answer

A)   zero
B)   1
C)   2
D)   4
E)   6F)  none of theseG) A) and D)
H) B) and E)

Question 10

Which of the following enzymes catalyzes the cleavage of fructose bisphosphate into two 3-carbon units?

Accepted Answer

A)   Aldolase
B)   Enolase
C)   An isomerase
D)   A mutase
E)   None of these enzymes carries out that reaction.F) A) and B)
G) All of the above

Question 11

The nicotinamide-binding region in glyceraldehyde-3-phosphate dehydrogenase is similar to all other NAD binding domains.

Accepted Answer

A) True 
 B)False

Question 12

The binding of glucose to hexokinase

Accepted Answer

A)   is an example of lock-and-key binding of a substrate to the active site of an enzyme.
B)   is an example of induced-fit binding of a substrate to the active site of an enzyme.
C)   differs from the binding of substrates to other kinases.
D)   is not well characterized.E) A) and B)
F) C) and D)

Question 13

The percentage of energy captured as ATP during the conversion of glucose to lactate is closest to

Accepted Answer

A)   10%.
B)   30%.
C)   50%.
D)   75%.
E)   90%.F) A) and E)
G) A) and D)

Question 14

In the conversion of glyceraldehyde 3-phosphate to 1,3-bisphosphoglycerate

Accepted Answer

A)   an alcohol group is phosphorylated.
B)   an alcohol is oxidized to an aldehyde.
C)   an alcohol is oxidized to a carboxylic acid.
D)   an aldehyde is oxidized to a carboxylic acid.E) B) and C)
F) A) and B)

Question 15

The step that commits the cell to metabolize glucose is catalyzed by

Accepted Answer

A)   hexokinase.
B)   phosphoglucomutase.
C)   aldolase.
D)   phosphofructokinase.E) B) and D)
F) A) and C)

Question 16

The ΔG values for glycolytic reactions at physiological conditions may be exergonic, even though the ΔG°' at "standard" conditions, may be endergonic.

Accepted Answer

A) True 
 B)False

Question 17

How many enzymes of glycolysis are control points for the pathway?

Accepted Answer

A)   1
B)   2
C)   3
D)   4
E)   All the enzymes serve as control points.F) B) and C)
G) C) and D)

Question 18

In the conversion of glucose to pyruvate, how many of the actual steps involve electron transfer?

Accepted Answer

A)   none
B)   1
C)   2
D)   3
E)   4F) B) and E)
G) C) and E)

Question 19

The fate of NADH from glycolysis depends on whether conditions are anaerobic or aerobic.

Accepted Answer

A) True 
 B)False

Question 20

Which of the following is not an end product of glucose metabolism via either aerobic or anaerobic means?

Accepted Answer

A)   ethanol
B)   carbon dioxide
C)   lactate
D)   fructose
E)   all of these are end products of glucose metabolismF) All of the above
G) A) and D)

Exam 17: Glycolysis

The ΔG values for glycolytic reactions at physiological conditions may be exergonic, even though the ΔG°' at "standard" conditions, may be endergonic.

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The fate of pyruvate produced during glycolysis depends primarily on the availability of

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Which of the following enzymes of glycolysis is not involved in regulation of the pathway?

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Consider the following information: phosphoenolpyruvate → pyruvate ΔG°' = −61.9 kJ/mol ADP + Pi → ATP ΔG°' = +30.5 kJ/mol How many molecules of ATP might theoretically have been produced when coupled to the conversion of one molecule phosphoenolpyruvate to pyruvate?

Correct AnswerverifiedShow Answer

Which of the following enzymes catalyzes the cleavage of fructose bisphosphate into two 3-carbon units?

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In the conversion of glucose to pyruvate, how many of the actual steps involve electron transfer?

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The nicotinamide-binding region in glyceraldehyde-3-phosphate dehydrogenase is similar to all other NAD binding domains.

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During anaerobic metabolism in yeast, the carbons of glucose end up in

Correct AnswerverifiedShow Answer

The fate of NADH from glycolysis depends on whether conditions are anaerobic or aerobic.

Correct AnswerverifiedShow Answer

In the conversion of glyceraldehyde 3-phosphate to 1,3-bisphosphoglycerate

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The step that commits the cell to metabolize glucose is catalyzed by

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The binding of glucose to hexokinase

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The phosphorylation of fructose 6-phosphate to fructose-1,6-bisphosphate is the committed step in glycolysis because

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The percentage of energy captured as ATP during the conversion of glucose to lactate is closest to

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How many enzymes of glycolysis are control points for the pathway?

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Which of the following is not an end product of glucose metabolism via either aerobic or anaerobic means?

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During anaerobic metabolism in red blood cells, the carbons of glucose end up in

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The equilibrium for isomerization of dihydroxyacetone phosphate to glyceraldehyde-3-phosphate is favored because

Correct AnswerverifiedShow Answer

How many steps in glycolysis have ATP as a substrate or product?

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During glycolysis, ATP is synthesized from ADP and a phosphate group transferred from an acid anhydride.

Correct AnswerverifiedShow Answer

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Consider the following information: phosphoenolpyruvate → pyruvate ΔG°' = −61.9 kJ/mol ADP + P_i → ATP ΔG°' = +30.5 kJ/mol How many molecules of ATP might theoretically have been produced when coupled to the conversion of one molecule phosphoenolpyruvate to pyruvate?

Correct Answer
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