Use the following information to answer the questions below.
In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate (1) loses a carbon, which is given off as a molecule of CO₂, (2) is oxidized to form a two-carbon compound called acetate, and (3) is bonded to coenzyme A.
-Why is coenzyme A, a sulphur-containing molecule derived from a B vitamin, added?
A)because sulphur is needed for the molecule to enter the mitochondrion
B)in order to utilize this portion of a B vitamin that would otherwise be a waste product from another pathway
C)to provide a relatively unstable molecule whose acetyl portion can be readily transferred to a compound in the citric acid cycle
D)because it drives the reaction that regenerates NAD⁺
E)in order to remove one molecule of CO₂

Question

Quizplus · Accepted Answer

Coenzyme A is added to pyruvate to create Acetyl-CoA, a relatively unstable molecule whose acetyl portion can be readily transferred to a compound in the citric acid cycle. This transfer of the acetyl portion of Acetyl-CoA provides energy for the cycle.

Use the Following Information to Answer the Questions Below