Question 1

If the ratio of NADP+ to NADPH were high, the

Accepted Answer

A)   net production of ATP would occur.
B)   pentose phosphate pathway oxidative phase would be activated.
C)   cellular levels of nucleotides would have to increase from an activated pentose phosphate pathway.
D)   pentose phosphate pathway would be inhibited.E) C) and D)
F) B) and D)

Question 2

Which of the following molecules would activate phosphofructokinase 1 (PFK1) ?

Accepted Answer

A)   NADH
B)   AMP
C)   ATP
D)   pyruvateE) A) and C)
F) B) and C)

Question 3

The conversion of pyruvate to phosphoenolpyruvate (PEP)  in gluconeogenesis

Accepted Answer

A)   requires the net input of two equivalents of NADH.
B)   occurs in two steps and is catalyzed by the enzymes pyruvate carboxylase and phosphoenolpyruvate carboxykinase.
C)   is a thermodynamically spontaneous reaction that gives rise to a stable product.
D)   requires lactate as a precursor.E) B) and C)
F) A) and D)

Question 4

Which enzyme in the pentose phosphate pathway is regulated to control flux through the pathway?

Accepted Answer

A)   glucose-6-phosphate dehydrogenase
B)   transaldolase
C)   6-phosphogluconate dehydrogenase
D)   ribulose-5-phosphate epimeraseE) A) and C)
F) B) and D)

Question 5

Name the four enzymes of the gluconeogenesis pathway that are NOT found in the glycolysis pathway.

Accepted Answer

Pyruvate carboxylase, phosphoe...

Question 6

Which enzyme class catalyzes the following pentose phosphate pathway reaction?

Accepted Answer

A)   lyase
B)   transferase
C)   oxidoreductase
D)   isomeraseE) All of the above
F) B) and D)

Question 7

Name each of the distinct catalytic activities of the debranching enzyme.

Accepted Answer

The debranching enzyme approaches a bran...

Question 8

Which enzyme in the glycolysis pathway catalyzes a reaction that requires two enzymes to reverse in the gluconeogenesis pathway?

Accepted Answer

A)   pyruvate kinase
B)   phosphofructokinase I
C)   pyruvate dehydrogenase
D)   glycogen phosphorylaseE) None of the above
F) C) and D)

Question 9

During vigorous exercise the lactate produced in the muscle travels to the liver for recycling. Explain why starting with lactate is beneficial for the liver gluconeogenesis pathway.

Accepted Answer

Lactate in the liver (1) can be converte...

Question 10

Gluconeogenesis would most likely be allosterically activated simultaneously along with which other metabolic process?

Accepted Answer

A)   glycolysis
B)   pentose phosphate pathway
C)   glycogen synthesis
D)   TCA cycleE) C) and D)
F) A) and B)

Question 11

What enzyme class in the nonoxidative phase of the pentose phosphate pathway allows for the reaction of ribose-5-phosphate and xylulose-5-phosphate to produce glyceraldehyde-3-phosphate and seduheptulose-7-phosphate?

Accepted Answer

A)   isomerase
B)   hydrolase
C)   transferase
D)   oxidoreductaseE) B) and C)
F) All of the above

Question 12

Gluconeogenesis is favored when citrate levels are , when AMP levels are __________, and when ATP levels are _.

Accepted Answer

A)   low; low; high
B)   high; low; high
C)   low; high; low
D)   high; high; lowE) None of the above
F) All of the above

Question 13

In the gluconeogenesis pathway, the enzyme glucose-6-phosphatase reverses which step in glycolysis?

Accepted Answer

A)   the formation of glucose
B)   the reaction catalyzed by pyruvate dehydrogenase
C)   the reaction catalyzed by hexokinase
D)   the formation of fructose-1,6-bisphosphateE) A) and D)
F) C) and D)

Question 14

Which of the following molecules might inhibit the regulated enzymes in glycolysis?

Accepted Answer

A)   NAD+
B)   ATP
C)   AMP
D)   fructose-2,6-bisphosphateE) A) and D)
F) B) and C)

Question 15

Which enzyme in the pentose phosphate pathway catalyzes the following reaction?

Accepted Answer

A)   glucose-6-phosphate dehydrogenase
B)   transaldolase
C)   6-phosphogluconate dehydrogenase
D)   ribulose-5-phosphate epimeraseE) A) and B)
F) B) and C)

Question 16

The Cori cycle

Accepted Answer

A)   requires both glycolysis and gluconeogenesis pathways.
B)   removes lactic acid from liver cells and delivers it to muscle cells.
C)   involves the regeneration of NADH equivalents for the working muscles.
D)   converts glucose into lactic acid.E) B) and D)
F) B) and C)

Question 17

Name the enzymes in the glycolysis or gluconeogenesis pathway that could be inhibited by ATP.

Accepted Answer

In glycolysis, enzymes that ar...

Question 18

The gluconeogenesis reaction shown below is missing some reactants and products. What class of enzyme catalyzes this reaction?

Accepted Answer

A)   lyase
B)   hydrolase
C)   transferase
D)   oxidoreductaseE) A) and B)
F) None of the above

Question 19

The opposing glycolysis and gluconeogenesis enzymes hexokinase and glucose-6-phosphatase are located with which cellular locations, respectively?

Accepted Answer

Hexokinase is found in the cyt...

Question 20

What class of enzymes in the oxidative phase of the pentose phosphate pathway is responsible for the production of NADPH?

Accepted Answer

Dehydrogen...

Exam 14: Carbohydrate Metabolism

Which of the following molecules might inhibit the regulated enzymes in glycolysis?

Correct AnswerverifiedShow Answer

Gluconeogenesis is favored when citrate levels are , when AMP levels are __________, and when ATP levels are _.

Correct AnswerverifiedShow Answer

Which enzyme in the pentose phosphate pathway is regulated to control flux through the pathway?

Correct AnswerverifiedShow Answer

What enzyme class in the nonoxidative phase of the pentose phosphate pathway allows for the reaction of ribose-5-phosphate and xylulose-5-phosphate to produce glyceraldehyde-3-phosphate and seduheptulose-7-phosphate?

Correct AnswerverifiedShow Answer

Which enzyme in the pentose phosphate pathway catalyzes the following reaction?

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What class of enzymes in the oxidative phase of the pentose phosphate pathway is responsible for the production of NADPH?

Correct AnswerverifiedDehydrogen...View AnswerShow Answer

The opposing glycolysis and gluconeogenesis enzymes hexokinase and glucose-6-phosphatase are located with which cellular locations, respectively?

Correct AnswerverifiedHexokinase is found in the cyt...View AnswerShow Answer

Name the four enzymes of the gluconeogenesis pathway that are NOT found in the glycolysis pathway.

Correct AnswerverifiedPyruvate carboxylase, phosphoe...View AnswerShow Answer

The gluconeogenesis reaction shown below is missing some reactants and products. What class of enzyme catalyzes this reaction?

Correct AnswerverifiedShow Answer

Which enzyme in the glycolysis pathway catalyzes a reaction that requires two enzymes to reverse in the gluconeogenesis pathway?

Correct AnswerverifiedShow Answer

Gluconeogenesis would most likely be allosterically activated simultaneously along with which other metabolic process?

Correct AnswerverifiedShow Answer

Which of the following molecules would activate phosphofructokinase 1 (PFK1) ?

Correct AnswerverifiedShow Answer

In the gluconeogenesis pathway, the enzyme glucose-6-phosphatase reverses which step in glycolysis?

Correct AnswerverifiedShow Answer

During vigorous exercise the lactate produced in the muscle travels to the liver for recycling. Explain why starting with lactate is beneficial for the liver gluconeogenesis pathway.

Correct AnswerverifiedLactate in the liver (1) can be converte...View AnswerShow Answer

Which enzyme class catalyzes the following pentose phosphate pathway reaction?

Correct AnswerverifiedShow Answer

The Cori cycle

Correct AnswerverifiedShow Answer

If the ratio of NADP+ to NADPH were high, the

Correct AnswerverifiedShow Answer

The conversion of pyruvate to phosphoenolpyruvate (PEP) in gluconeogenesis

Correct AnswerverifiedShow Answer

Name the enzymes in the glycolysis or gluconeogenesis pathway that could be inhibited by ATP.

Correct AnswerverifiedIn glycolysis, enzymes that ar...View AnswerShow Answer

Name each of the distinct catalytic activities of the debranching enzyme.

Correct AnswerverifiedThe debranching enzyme approaches a bran...View AnswerShow Answer

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Dehydrogen...
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Hexokinase is found in the cyt...
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Pyruvate carboxylase, phosphoe...
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Lactate in the liver (1) can be converte...
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If the ratio of NADP⁺to NADPH were high, the

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In glycolysis, enzymes that ar...
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The debranching enzyme approaches a bran...
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