Glycolysis Quiz
Questions: 16 · 10 minutes
1. During the glyceraldehyde-3-phosphate dehydrogenase reaction, what happens to NAD+?
It accepts electrons and is reduced to NADH
It donates a phosphate group and becomes NADP+
It donates electrons and is oxidized to NADH
It transfers an acetyl group and becomes acetyl-CoA
2. What happens to ATP during the energy-investment phase of glycolysis?
Four ATP are produced before glucose is split
Two ATP are consumed to phosphorylate pathway intermediates
One ATP is consumed and one ATP is produced, giving no change
Two ATP are converted directly into NADH
3. A cell's hexokinase activity is sharply inhibited. Which immediate change is most likely?
More phosphoenolpyruvate is converted into pyruvate
More fructose-1,6-bisphosphate is split into three-carbon molecules
Less glucose is converted into glucose-6-phosphate
Less NADH is oxidized by the electron transport chain
4. Which cellular condition would most strongly favor increased phosphofructokinase-1 activity and faster glycolytic flux?
High AMP and low ATP
High ATP and low AMP
Low ADP and abundant citrate
High ATP and high citrate
5. A cell has glucose, ADP, NAD+, and functioning glycolytic enzymes, but no oxygen. Which statement about glycolysis is correct?
Glycolysis must stop because oxygen is a direct reactant in its first step
Glycolysis itself can proceed without oxygen if NAD+ is regenerated
Glycolysis can proceed only if mitochondria produce the required pyruvate
Glycolysis switches from ATP production to direct oxygen production
6. What is the net yield of glycolysis from one glucose molecule under standard accounting?
Two acetyl-CoA, two ATP, and two FADH₂
One pyruvate, four ATP, and no NADH
Two pyruvate, two ATP, and two NADH
Two lactate, four ATP, and two NADPH
7. In a eukaryotic cell, where does glycolysis take place?
In the nucleus
In the mitochondrial matrix
On the inner mitochondrial membrane
In the cytosol
8. After one six-carbon glucose molecule is split and triose phosphates are rearranged, which molecules proceed through the payoff phase?
One molecule of dihydroxyacetone phosphate only
One glyceraldehyde-3-phosphate and one pyruvate
Two molecules of fructose-6-phosphate
Two molecules of glyceraldehyde-3-phosphate
9. Which equation best represents the reaction catalyzed by pyruvate kinase?
Pyruvate + ATP → phosphoenolpyruvate + ADP
3-phosphoglycerate → 2-phosphoglycerate
Phosphoenolpyruvate + ADP → pyruvate + ATP
Pyruvate + NADH → lactate + NAD+
10. An inhibitor blocks glyceraldehyde-3-phosphate dehydrogenase. Which direct effect should occur?
Glucose phosphorylation increases because ATP is formed at the blocked step
Fructose-1,6-bisphosphate can no longer split into three-carbon products
Formation of 1,3-bisphosphoglycerate and NADH decreases
Pyruvate is converted to acetyl-CoA within the cytosol
11. Which reaction is the major committed step of glycolysis?
Fructose-6-phosphate to fructose-1,6-bisphosphate by phosphofructokinase-1
Dihydroxyacetone phosphate to glyceraldehyde-3-phosphate by triose phosphate isomerase
Phosphoenolpyruvate to pyruvate by pyruvate kinase
Glucose to glucose-6-phosphate by hexokinase
12. A laboratory inhibitor blocks enolase, which converts 2-phosphoglycerate to phosphoenolpyruvate. Which pattern is most likely?
Phosphoenolpyruvate accumulates while 2-phosphoglycerate falls
2-phosphoglycerate accumulates while phosphoenolpyruvate formation falls
Fructose-6-phosphate falls because enolase phosphorylates it
Pyruvate accumulates while glucose use stops at hexokinase
13. Why are mature human red blood cells especially dependent on glycolysis for ATP production?
They lack mitochondria
They cannot transport glucose across their membranes
They contain no enzymes for converting pyruvate to lactate
They use fatty acids exclusively as their cytosolic fuel
14. A cell completes glycolysis for one glucose molecule. Four ATP were generated in the payoff phase, and the usual investment occurred. What is the net ATP gain?
One ATP
Two ATP
Four ATP
Six ATP
15. Which pair of enzymes catalyzes the ATP-producing reactions of glycolysis?
Hexokinase and phosphofructokinase-1
Aldolase and triose phosphate isomerase
Glyceraldehyde-3-phosphate dehydrogenase and enolase
Phosphoglycerate kinase and pyruvate kinase
16. During strenuous activity, muscle cells may convert pyruvate to lactate. How does this help glycolysis continue?
It supplies an extra ATP at the pyruvate kinase step
It returns pyruvate directly to glucose without using energy
It converts NAD+ into NADH for the electron transport chain
It regenerates NAD+ needed for glyceraldehyde-3-phosphate oxidation