Multiple Choice
In one turn of the citric acid cycle per acetyl-CoA (excluding NADH produced by pyruvate dehydrogenase), how many molecules of NADH are produced?
10
views
Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism
Citric Acid Cycle 1
Multiple Choice
In one turn of the citric acid (Krebs) cycle per acetyl-CoA, how many molecules of are produced?
A
B
C
D
Verified step by step guidance1
Recall that the citric acid cycle (Krebs cycle) processes one acetyl-CoA molecule per turn, generating several reduced coenzymes including NADH and FADH2.
Identify the specific step(s) in the cycle where FAD is reduced to FADH2. This occurs during the conversion of succinate to fumarate catalyzed by the enzyme succinate dehydrogenase.
Understand that this step produces exactly one molecule of FADH2 per turn of the cycle because only one succinate molecule is oxidized per acetyl-CoA entering the cycle.
Note that other reduced coenzymes like NADH are produced at different steps, but the question specifically asks about FADH2 molecules.
Conclude that for each acetyl-CoA molecule entering the citric acid cycle, one molecule of FADH2 is produced.
Related Videos
Related Practice
