Exam 2 (2023): Lecture 16

Question 1

8. Fructose and galactose must enter the glycolytic pathway through specific glycolytic intermediates to be further processed to pyruvate. In the muscle & adipose tissue, fructose enters glycolysis at the intermediate __________, while galactose enters glycolysis at the intermediate ____________.

A) glucose 6-phosphate; fructose 6-phosphate

B) fructose 1,6-bisphosphate; 1,3-bisphosphoglycerate

C) fructose 6-phosphate; glucose 6-phosphate

D) dihydroxyacetone phosphate; glyceraldehyde-3-phosphate E) fructose 1-phosphate; glucose 1-phosphate

Answer 1

C) fructose 6-phosphate; glucose 6-phosphate

Question 2

9. In glycolysis, ____________ is the name of the enzyme that catalyzes the redox (oxidation- reduction) reaction, while ______________ is the name of the “kinetically perfect” enzyme.

A) Hexokinase ; phosphofructokinase

B) Glyceraldehyde 3-phosphate dehydrogenase ; triose phosphate isomerase

C) Phosphofructokinase ; triose phosphate isomerase

D) Glyceraldehyde 3-phosphate dehydrogenase ; pyruvate kinase

E) Phosphoglycerate kinase ; enolase

Answer 2

B) Glyceraldehyde 3-phosphate dehydrogenase ; triose phosphate isomerase

Question 3

10. In glycolysis, _____________ is one of the two enzymes that catalyzes an “energy investment” step, while _______________ is one of the two enzymes that catalyzes an “energy harvesting” step.

A) hexokinase; phosphofructokinase-1

B) phosphoglycerate kinase; phosphofructokinase-1

C) pyruvate kinase; hexokinase

D) phosphofructokinase-1; phosphoglycerate kinase

E) phosphoglycerate kinase; pyruvate kinase

Answer 3

D) phosphofructokinase-1; phosphoglycerate kinase

Question 4

11. Use the following reactions to answer the question below:

I. 1,3-bisphosphoglycerate (BPG) –>
3-phosphoglycerate(3PG)

II. Glucose –> glucose-6-phosphate (G6P)

III. 2-Phosphoglycerate (2PG) –>
3-phosphoglycerate (3PG)

IV. Glycerol-3-phosphate (GAP) –>
1,3-bisphosphoglycerate (BPG)

V. Glucose-6-phosphate (G6P) –> fructose-6-phosphate (F6P)

Reaction _____ requires ATP as a substrate, while reaction _______ requires NAD+ as a substrate.

A) I; II
B) II; III
C) II; IV
D) IV; V
E) V; I

Answer 4

C) II; IV

Question 5

12. In glycolysis, glyceraldehyde is oxidized to _____ which can transfer a phosphate to _____.

A) phosphoenolpyruvate; ADP
B) phosphoenolpyruvate; AMP
C) 1,3-bisphosphoglycerate; ADP
D) 1,3-bisphosphoglycerate; AMP

Answer 5

C) 1,3-bisphosphoglycerate; ADP