Page 1 of 47
BIOCHEM 210 Module 7 Practice Exam:
Metabolism (Glycolysis, CAC & Oxidative
Phosphorylation) Actual Exam Questions
with Correct Answers & Explanations |
Graded A+ Study Guide
1. Where in the cell does glycolysis occur?
✅ Cytosol
Rationale: Glycolysis takes place in the cytoplasm, not in
mitochondria.
2. How many net ATP are produced from one glucose in
glycolysis?
✅ 2 ATP
Rationale: 4 ATP produced, 2 ATP consumed → net 2 ATP.
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3. What is the first committed step of glycolysis?
✅ Phosphofructokinase-1 (PFK-1) reaction
Rationale: Fructose-6-phosphate → fructose-1,6-bisphosphate;
commits glucose to glycolysis.
4. Which enzyme converts glucose to glucose-6-phosphate?
✅ Hexokinase (or glucokinase in liver)
Rationale: Uses ATP to phosphorylate glucose, trapping it in the
cell.
5. What cofactor is used by glyceraldehyde-3-phosphate
dehydrogenase?
✅ NAD⁺
Rationale: NAD⁺ accepts a hydride to become NADH.
6. True/False: Glycolysis requires oxygen.
✅ False
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Rationale: Glycolysis is anaerobic; oxygen is not required but
allows further ATP production via oxidative phosphorylation.
7. Which glycolysis step produces the first ATP (substrate-level
phosphorylation)?
✅ 1,3-Bisphosphoglycerate → 3-Phosphoglycerate
(phosphoglycerate kinase)
Rationale: Transfers high-energy phosphate to ADP.
8. Which step produces the second ATP in glycolysis?
✅ Phosphoenolpyruvate → Pyruvate (pyruvate kinase)
Rationale: Another substrate-level phosphorylation.
9. What is the end product of glycolysis under aerobic
conditions?
✅ Pyruvate
Rationale: Pyruvate enters the mitochondria for CAC.
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10. Under anaerobic conditions, pyruvate is converted to ____
in humans.
✅ Lactate
Rationale: Lactate dehydrogenase regenerates NAD⁺ for
continued glycolysis.
11. Which enzyme is inhibited by ATP and activated by AMP?
✅ PFK-1
Rationale: Key regulatory enzyme; responds to energy charge.
12. Fructose-2,6-bisphosphate (F-2,6-BP) activates which
enzyme?
✅ PFK-1
Rationale: F-2,6-BP is a potent allosteric activator, overriding
ATP inhibition.
BIOCHEM 210 Module 7 Practice Exam:
Metabolism (Glycolysis, CAC & Oxidative
Phosphorylation) Actual Exam Questions
with Correct Answers & Explanations |
Graded A+ Study Guide
1. Where in the cell does glycolysis occur?
✅ Cytosol
Rationale: Glycolysis takes place in the cytoplasm, not in
mitochondria.
2. How many net ATP are produced from one glucose in
glycolysis?
✅ 2 ATP
Rationale: 4 ATP produced, 2 ATP consumed → net 2 ATP.
,Page 2 of 47
3. What is the first committed step of glycolysis?
✅ Phosphofructokinase-1 (PFK-1) reaction
Rationale: Fructose-6-phosphate → fructose-1,6-bisphosphate;
commits glucose to glycolysis.
4. Which enzyme converts glucose to glucose-6-phosphate?
✅ Hexokinase (or glucokinase in liver)
Rationale: Uses ATP to phosphorylate glucose, trapping it in the
cell.
5. What cofactor is used by glyceraldehyde-3-phosphate
dehydrogenase?
✅ NAD⁺
Rationale: NAD⁺ accepts a hydride to become NADH.
6. True/False: Glycolysis requires oxygen.
✅ False
,Page 3 of 47
Rationale: Glycolysis is anaerobic; oxygen is not required but
allows further ATP production via oxidative phosphorylation.
7. Which glycolysis step produces the first ATP (substrate-level
phosphorylation)?
✅ 1,3-Bisphosphoglycerate → 3-Phosphoglycerate
(phosphoglycerate kinase)
Rationale: Transfers high-energy phosphate to ADP.
8. Which step produces the second ATP in glycolysis?
✅ Phosphoenolpyruvate → Pyruvate (pyruvate kinase)
Rationale: Another substrate-level phosphorylation.
9. What is the end product of glycolysis under aerobic
conditions?
✅ Pyruvate
Rationale: Pyruvate enters the mitochondria for CAC.
, Page 4 of 47
10. Under anaerobic conditions, pyruvate is converted to ____
in humans.
✅ Lactate
Rationale: Lactate dehydrogenase regenerates NAD⁺ for
continued glycolysis.
11. Which enzyme is inhibited by ATP and activated by AMP?
✅ PFK-1
Rationale: Key regulatory enzyme; responds to energy charge.
12. Fructose-2,6-bisphosphate (F-2,6-BP) activates which
enzyme?
✅ PFK-1
Rationale: F-2,6-BP is a potent allosteric activator, overriding
ATP inhibition.
