Question 1

Which of the following best describes the two distinct phases of glycolysis?

Accepted Answer

An energy-investment phase where ATP is consumed, followed by an energy-generation phase where ATP and NADH are produced.

Question 2

During the energy-investment phase of glycolysis, how many ATP molecules are consumed per molecule of glucose?

Accepted Answer

$2$

Question 3

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

Accepted Answer

Hexokinase; glucose-6-phosphate

Question 4

In the energy-generation phase of glycolysis, which molecule is directly responsible for substrate-level phosphorylation of ADP to ATP?

Accepted Answer

Phosphoenolpyruvate (PEP)

Question 5

What is the net yield of ATP and NADH per molecule of glucose after glycolysis is complete?

Accepted Answer

$2$ ATP and $2$ NADH

Question 6

Which glycolytic enzyme catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate?

Accepted Answer

Phosphofructokinase

Question 7

If a mutation rendered phosphoglycerate kinase nonfunctional, which of the following would be directly affected?

Accepted Answer

Substrate-level phosphorylation producing ATP from 1,3-bisphosphoglycerate

Question 8

Which reaction in glycolysis is considered highly exergonic and essentially irreversible under physiological conditions?

Accepted Answer

Phosphofructokinase reaction

Question 9

During glycolysis, which molecule is oxidized to produce NADH?

Accepted Answer

Glyceraldehyde-3-phosphate

Question 10

Which of the following best explains why glycolysis can proceed under anaerobic conditions?

Accepted Answer

Pyruvate is converted to lactate, regenerating NAD$^+$ needed for glycolysis.

Question 11

Which enzyme catalyzes the final step of glycolysis, and what are the products?

Accepted Answer

Pyruvate kinase; pyruvate and ATP

Question 12

Which of the following is a correct summary equation for glycolysis?

Accepted Answer

$\mathrm{Glucose} + 2\ \mathrm{NAD}^+ + 2\ \mathrm{ADP} + 2\ \mathrm{P_i} \rightarrow 2\ \mathrm{Pyruvate} + 2\ \mathrm{NADH} + 2\ \mathrm{ATP} + 2\ \mathrm{H_2O}$

Question 13

Which glycolytic intermediate is the first to be split into two three-carbon molecules?

Accepted Answer

Fructose-1,6-bisphosphate

Question 14

A patient with a deficiency in triose phosphate isomerase would have impaired conversion between which two glycolytic intermediates?

Accepted Answer

Glyceraldehyde-3-phosphate and dihydroxyacetone phosphate

Question 15

Which step in glycolysis is responsible for the first ATP generation via substrate-level phosphorylation?

Accepted Answer

Phosphoglycerate kinase converting 1,3-bisphosphoglycerate to 3-phosphoglycerate

Question 16

Which of the following statements about the energy yield of glycolysis is correct?

Accepted Answer

Glycolysis consumes $2$ ATP and produces $4$ ATP, resulting in a net gain of $2$ ATP per glucose molecule.

Question 17

Which enzyme is responsible for the isomerization of glucose-6-phosphate to fructose-6-phosphate?

Accepted Answer

Glucose-6-phosphate isomerase

Question 18

Which glycolytic reaction involves the oxidation of an aldehyde group and the reduction of NAD$^+$ to NADH?

Accepted Answer

Glyceraldehyde-3-phosphate dehydrogenase converting glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate

Question 19

Which of the following is NOT a product of glycolysis?

Accepted Answer

CO$_2$

Glycolysis: Overview, Phases, and Reactions

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