Glycolysis MCQ Answers Winter 2015 PDF

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Answers to Practice Exam Questions: Glycolysis (Hint: see textbook pages 306-307 for a summary of the reactions in glycolysis.) 1.

Which of the following phosphorylated compounds would you predict to be a "low-energy" intermediate in metabolism, relative to the others?

A. B. C. D. E.

ATP 1,3-bisphosphoglycerate Glucose 6-phosphate Phosphoenolpyruvate NADH

2.

Which pair below correctly matches an enzyme with its effector?

A. B. C. D. E.

Phosphofructokinase-1 / fructose-1,6-bisphosphate Pyruvate kinase / phosphoenolpyruvate Hexokinase / glucose 1-phosphate Pyruvate kinase / fructose-1,6-bisphosphate Hexokinase / fructose-1,6-bisphosphate

3.

Which of the following does NOT occur in the reactions of glycolysis between fructose-1,6bisphosphate and 1,3-bisphosphoglycerate?

A. B. C. D. E.

Phosphoryl transfer An isomerization The formation of a high-energy intermediate Oxidation All of these occur.

4.

In the oxidation reaction of glycolysis, which of the following statements is TRUE?

A. B. C. D. E.

It is an irreversible reaction. It is a regulated step of glycolysis. During the catabolism of glucose to pyruvate, NAD+ is oxidized. Some of the energy from the oxidation reaction is captured by the formation of ATP. The reaction halts in the absence of inorganic phosphate.

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5.

Which of the following combinations correctly identifies net production when 1 mol of fructose 6-phosphate is converted to pyruvate during glycolysis?

A. B. C. D. E.

1 mol of NAD+ and 3 mol of ATP 2 mol of NAD+ and 3 mol of ATP 1 mol of NADH and 2 mol of ATP 2 mol of NADH and 2 mol of ATP 2 mol of NADH and 3 mol of ATP

6.

Each of the following compounds is capable of undergoing hydrolysis of a phosphate group. Which hydrolysis will yield the smallest free energy change?

A. B. C. D. E.

1,3-bisphosphoglycerate Glucose 6-phosphate ADP Phosphoenolpyruvate ATP

7.

The reactions in glycolysis catalyzed by phosphofructokinase-1 and pyruvate kinase are similar in that:

A. B. C. D. E.

They both use ATP. They are both catalyzed by allosteric enzymes. They are both reversible. They are both substrate-level phosphorylation reactions. They both involve three-carbon compounds.

8.

Which of the following does NOT occur in the steps of glycolysis between 1,3-bisphosphoglycerate and phosphoenolpyruvate?

A. B. C. D. E.

ATP synthesis An isomerization The formation of a high-energy intermediate Phosphoryl transfer Oxidation

9.

Phosphoenolpyruvate is an inhibitor of hexokinase activity.

A. True B. False

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10. Which of the following enzymes catalyzes an "energy investment" reaction in glycolysis? A. B. C. D. E.

Hexokinase Phosphofructokinase-2 Pyruvate kinase Phosphoglycerate kinase A and B

11. Increasing the NADH/NAD+ ratio will decrease the rate of 1,3-bisphosphoglycerate synthesis by glyceraldehyde 3-phosphate dehydrogenase. A. True B. False

12. Which of the following is a method of regulating PFK-1 activity? A. B. C. D. E.

Allosteric inhibition by ADP. Product inhibition by fructose-1,6-bisphosphate. Feed-forward activation by phosphoenolpyruvate. Allosteric activation by ADP. Allosteric activation by glucose 6-phosphate.

13. Which of the following enzymes catalyzes a substrate-level phosphorylation reaction in the catabolism of glucose? A. B. C. D. E.

Pyruvate kinase Phosphofructokinase-1 Glyceraldehyde 3-phosphate dehydrogenase Hexokinase B and D

14. The conversion of 1 mol of glucose 6-phosphate to 2 mol of pyruvate is accompanied by a net gain of: A. B. C. D.

2 mol of ATP and 1 mol of NADH 2 mol of ATP and 2 mol of NADH 3 mol of ATP and 1 mol of NADH 3 mol of ATP and 2 mol of NADH

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15. Which of the following is a high-energy intermediate produced in glycolysis? A. B. C. D. E.

F-1,6-BP GAP 1,3-BPG 2-PG Phosphocreatine

16. Which of the following statements is TRUE regarding the glycolytic pathway? A. The pathway only operates under anaerobic conditions. B. The pathway is regulated by allostery and product inhibition among other mechanisms. C. The balanced equation for glycolysis is: glucose + NAD+ + 2ADP + 2Pi  2 pyruvate + H+ + NADH + 2ATP + 2H2O D. Hexokinase catalyses a substrate-level phosphorylation reaction. 17. If radioactively-labeled inorganic phosphate (32Pi) is added to a cell-free liver extract, which of the following molecules will become radiolabeled during one round of glycolysis? A. B. C. D. E.

Phosphoenolpyruvate Glyceraldehyde 3-phosphate 1,3-bisphosphoglycerate ATP C and D

18. What is the net energy gain when 1 mol of dihydroxyacetone phosphate is converted to pyruvate? A. B. C. D. E.

1 mol of NADH and 1 mol of ATP 1 mol of NADH and 2 mol of ATP 1 mol of NADH and 4 mol of ATP 2 mol of NADH and 2 mol of ATP 2 mol of NADH and 4 mol of ATP

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