$$\text{Glucose} + 2\text{ADP} + 2\text{NAD}^+ \rightarrow 2\text{Pyruvate} + 2\text{ATP} + 2\text{NADH} + 2\text{H}_2\text{O} + 2\text{H}^+$$

$$\Delta G^\circ' = -2840 \text{ kJ/mol}$$

Question 1

Which enzyme catalyzes the first committed step of glycolysis, and what is the product of this reaction?

Accepted Answer

Phosphofructokinase-1; fructose-1,6-bisphosphate

Question 2

What is the net ATP yield from glycolysis per molecule of glucose under anaerobic conditions?

Accepted Answer

$$2$$

Question 3

Which of the following best describes the role of phosphoglucose isomerase in glycolysis?

Accepted Answer

It converts glucose-6-phosphate to fructose-6-phosphate.

Question 4

During glycolysis, which step is responsible for the production of NADH?

Accepted Answer

Glyceraldehyde-3-phosphate dehydrogenase

Question 5

Which of the following reactions in glycolysis is an example of substrate-level phosphorylation?

Accepted Answer

Conversion of phosphoenolpyruvate to pyruvate by pyruvate kinase

Question 6

What is the overall chemical equation for glycolysis, including ATP and NADH production?

Accepted Answer

$$	ext{Glucose} + 2	ext{ADP} + 2	ext{NAD}^+ ightarrow 2	ext{Pyruvate} + 2	ext{ATP} + 2	ext{NADH} + 2	ext{H}_2	ext{O} + 2	ext{H}^+$$

Question 7

Which glycolytic intermediate is cleaved by aldolase to produce two three-carbon molecules?

Accepted Answer

Fructose-1,6-bisphosphate

Question 8

In the mechanism of triose phosphate isomerase, which amino acid acts as a general acid/base catalyst?

Accepted Answer

Glu-165

Question 9

Which step in glycolysis is considered irreversible under physiological conditions and is a key regulatory point?

Accepted Answer

Phosphofructokinase-1 catalyzed conversion of fructose-6-phosphate to fructose-1,6-bisphosphate

Question 10

Which of the following statements about the payoff phase of glycolysis is correct?

Accepted Answer

It produces NADH and ATP via substrate-level phosphorylation.

Question 11

A patient has a deficiency in phosphoglucose isomerase. Which glycolytic intermediate would you expect to accumulate?

Accepted Answer

Glucose-6-phosphate

Question 12

Which of the following best explains why phosphorylated intermediates are important in glycolysis?

Accepted Answer

They prevent intermediates from diffusing out of the cell.

Question 13

Which enzyme catalyzes the conversion of 2-phosphoglycerate to phosphoenolpyruvate?

Accepted Answer

Enolase

Question 14

What is the function of the Schiff base in the mechanism of Class I aldolases?

Accepted Answer

It stabilizes the carbanion intermediate during aldol cleavage.

Question 15

Which glycolytic enzyme is allosterically inhibited by ATP and activated by AMP?

Accepted Answer

Phosphofructokinase-1

Question 16

If a mutation caused triose phosphate isomerase to lose its catalytic efficiency, which product of glycolysis would decrease most significantly?

Accepted Answer

Pyruvate

Question 17

Which of the following is the correct standard free energy change ($$\Delta G^\circ') $$for the overall glycolytic reaction?

Accepted Answer

$$\Delta G^\circ' = -2840 	ext{ kJ/mol}$$

Question 18

Which glycolytic enzyme catalyzes the transfer of a phosphate group from 1,3-bisphosphoglycerate to ADP, forming ATP?

Accepted Answer

Phosphoglycerate kinase

Question 19

Which of the following statements about the mechanism of hexokinase is correct?

Accepted Answer

Hexokinase uses a random bi-bi mechanism for the transfer of the phosphate group.

Question 20

Which glycolytic intermediate is the first to have a high-energy acyl phosphate bond?

Accepted Answer

1,3-bisphosphoglycerate

Glycolysis: Pathway, Mechanisms, and Enzymatic Reactions

Study Guide - Practice Questions