Question 1

Draw the structure of the short glycogen disaccharide linked to glycogenin through its tyrosine amino acid.

Accepted Answer

The answer of Draw the structure of the short glycogen...

Question 2

In the glycogenesis pathway, what is the leaving group in the last step where glucose is added to the growing glycogen chain?

Accepted Answer

A)   UDP-glucose
B)   pi
C)   glucose-1-phosphate
D)   UDPE) A) and D)
F) A) and B)

Question 3

In the elongation of glycogen, activated glucose units are attached to which hydroxyl of the terminal residue of the growing glycogen chain?

Accepted Answer

A)   C-1
B)   C-3
C)   C-4
D)   C-6E) A) and B)
F) A) and C)

Question 4

Which of the following molecules is found in the nonoxidative phase of the pentose phosphate pathway?

Accepted Answer

A)   glucose-6-phosphate
B)   sedoheptulose-7-phosphate
C)   phosphoenolpyruvate
D)   CO2E) B) and D)
F) C) and D)

Question 5

What class of biomolecule is glycogenin?

Accepted Answer

A)   hormone
B)   carbohydrate
C)   enzyme
D)   lipidE) C) and D)
F) None of the above

Question 6

The main function of the pentose phosphate pathway is to provide

Accepted Answer

A)   the cell with backup capability when glycolysis is inhibited.
B)   energy and reducing power.
C)   a mechanism for the utilization of the carbon skeletons of excess amino acids.
D)   a source of ribose and NADPH.E) None of the above
F) A) and D)

Question 7

Which of the following is NOT a role played by the pentose phosphate pathway?

Accepted Answer

A)   converting pyruvate into TCA cycle intermediates
B)   making NADPH for other metabolic pathways
C)   converting 6C glucose into 5C ribose
D)   converting DNA backbone sugars into glycolysis intermediatesE) A) and B)
F) A) and C)

Question 8

The debranching enzyme does NOT catalyze the

Accepted Answer

A)   formation of  α\alphaα (1,6)  linkages.
B)   cleavage of  α\alphaα (1,6)  linkages.
C)   formation of  α\alphaα (1,4)  linkages.
D)   cleavage of  α\alphaα (1,4)  linkages. E) B) and D)
F) B) and C)

Question 9

The activation of glycogen phosphorylase will lead to a(n)  in blood glucose concentrations and is stimulated by the hormone _.

Accepted Answer

A)   decrease; insulin
B)   decrease; glucagon
C)   increase; insulin
D)   increase; glucagonE) All of the above
F) B) and C)

Question 10

The regulated reactions of gluconeogenesis have/are

Accepted Answer

A)   large positive  Δ\DeltaΔ G values.
B)   those that are counter to regulated reactions in glycolysis.
C)   reversible reactions.
D)   activated by molecules indicating a low energy charge in the cell. E) None of the above
F) A) and B)

Question 11

In the glycogenesis pathway, the role of the glucose-6-phosphate isomerization reaction is to

Accepted Answer

A)   create a more stable intermediate for the subsequent reaction.
B)   decrease the concentration of glucose-6-phosphate, thereby driving the pathway forward.
C)   ensure that the charged molecule stays in the cell.
D)   prepare the anomeric carbon for nucleophilic attack.E) A) and D)
F) None of the above

Question 12

Name the enzymes that catalyze the two opposing glycogen polymerization and depolymerization reactions found in glycogen synthesis and glycogen breakdown.

Accepted Answer

Glycogen synthase catalyzes gl...

Question 13

Which one of the following is involved in the breakdown of glycogen?

Accepted Answer

A)   inorganic phosphate
B)   ATP
C)   branching enzyme
D)   hexokinaseE) B) and D)
F) B) and C)

Question 14

Which enzyme uses cellular NADPH to regenerate reduced glutathione?

Accepted Answer

A)   glucose-6-phosphate dehydrogenase
B)   glutathione peroxidase
C)   glutathione reductase
D)   hemoglobinE) None of the above
F) B) and D)

Question 15

What is the cellular role of glutathione in red blood cells?

Accepted Answer

Glutathione acts as an antioxidant to pr...

Question 16

In the breakdown of glycogen, the debranching enzyme catalyzes the formation of

Accepted Answer

A)   "glucose-1-phosphate."
B)   "glucose."
C)   " α\alphaα (1,6)  branched glycogen."
D)   "glucose-6-phosphate." E) All of the above
F) None of the above

Question 17

Which pair of opposite enzymes in the glycolysis and gluconeogenesis pathway are not allosterically regulated but rather regulated by compartmentalization?

Accepted Answer

A)   pyruvate kinase/PEP carboxykinase
B)   phosphofructokinase 1/fructose-1,6-bisphosphatase
C)   phosphofructokinase 2/fructose-2,6-bisphosphatase
D)   hexokinase/glucose-6-phosphataseE) A) and B)
F) C) and D)

Question 18

How many moles of NADH are required in gluconeogenesis to convert 2 moles of pyruvate molecules into 1 mole of glucose?

Accepted Answer

A)   0
B)   1
C)   2
D)   4E) B) and C)
F) A) and C)

Question 19

What is the overall net reaction of the pentose phosphate pathway, where glucose-
6-phosphate is entirely converted to CO2? Please include any cofactors produced for the cell.

Accepted Answer

glucose-6-phosphate + 12 NADP<...

Question 20

Which of the following molecules would inhibit the regulated steps in gluconeogenesis?

Accepted Answer

A)   ATP
B)   ADP
C)   pyruvate
D)   NADHE) None of the above
F) B) and D)

Exam 14: Carbohydrate Metabolism

In the breakdown of glycogen, the debranching enzyme catalyzes the formation of

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In the elongation of glycogen, activated glucose units are attached to which hydroxyl of the terminal residue of the growing glycogen chain?

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The debranching enzyme does NOT catalyze the

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What is the cellular role of glutathione in red blood cells?

Correct AnswerverifiedGlutathione acts as an antioxidant to pr...View AnswerShow Answer

Name the enzymes that catalyze the two opposing glycogen polymerization and depolymerization reactions found in glycogen synthesis and glycogen breakdown.

Correct AnswerverifiedGlycogen synthase catalyzes gl...View AnswerShow Answer

Draw the structure of the short glycogen disaccharide linked to glycogenin through its tyrosine amino acid.

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Which enzyme uses cellular NADPH to regenerate reduced glutathione?

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Which of the following is NOT a role played by the pentose phosphate pathway?

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In the glycogenesis pathway, the role of the glucose-6-phosphate isomerization reaction is to

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The regulated reactions of gluconeogenesis have/are

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In the glycogenesis pathway, what is the leaving group in the last step where glucose is added to the growing glycogen chain?

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The activation of glycogen phosphorylase will lead to a(n) in blood glucose concentrations and is stimulated by the hormone _.

Correct AnswerverifiedShow Answer

What is the overall net reaction of the pentose phosphate pathway, where glucose- 6-phosphate is entirely converted to CO2? Please include any cofactors produced for the cell.

Correct Answerverifiedglucose-6-phosphate + 12 NADP<...View AnswerShow Answer

What class of biomolecule is glycogenin?

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Which of the following molecules is found in the nonoxidative phase of the pentose phosphate pathway?

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How many moles of NADH are required in gluconeogenesis to convert 2 moles of pyruvate molecules into 1 mole of glucose?

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Which one of the following is involved in the breakdown of glycogen?

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Which of the following molecules would inhibit the regulated steps in gluconeogenesis?

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The main function of the pentose phosphate pathway is to provide

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Which pair of opposite enzymes in the glycolysis and gluconeogenesis pathway are not allosterically regulated but rather regulated by compartmentalization?

Correct AnswerverifiedShow Answer

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Glutathione acts as an antioxidant to pr...
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Glycogen synthase catalyzes gl...
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

What is the overall net reaction of the pentose phosphate pathway, where glucose- 6-phosphate is entirely converted to CO₂? Please include any cofactors produced for the cell.

Correct Answer
verified
glucose-6-phosphate + 12 NADP<...
View Answer

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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