In the presence of oxygen, the three-carbon compound pyruvate can be catabolised in the citric acid cycle. First, however, the pyruvate (1) loses a carbon, which is given off as a molecule of CO₂, (2) is oxidised to form a two-carbon compound called acetate, and (3) is bonded to coenzyme A. Which of the following sets of products result from these reactions?
A) acetyl CoA, O₂, and ATP
B) acetyl CoA, FADH₂, and CO₂
C) acetyl CoA, NADH, and CO₂
D) acetyl CoA, NAD⁺, ATP, and CO₂

Question

Quizplus · Accepted Answer

The pyruvate loses a carbon to form CO₂, is oxidized to form a two-carbon compound called acetate, and is bonded to coenzyme A to form acetyl CoA. This reaction produces one molecule of NADH and one molecule of CO₂. Therefore, the set of products resulting from these reactions is acetyl CoA, NADH, and CO₂. Option A is incorrect because it includes O₂, which is not a product of the given reactions. Option B is incorrect because it includes FADH₂, which is not produced from pyruvate oxidation. Option D is incorrect because it includes NAD⁺ and ATP as products, which are not produced during pyruvate oxidation.

In the Presence of Oxygen, the Three-Carbon Compound Pyruvate Can