Question

In preparing pyruvate to enter the citric acid cycle, which of the following steps occurs?

A
Pyruvate is reduced, and a molecule of carbon dioxide is removed. The electrons removed in this process are used to oxidize NAD+ to NADH.
B
Pyruvate is oxidized, and a molecule of carbon dioxide is removed. The electrons removed in this process are donated to NADH to produce NAD+.
C
Pyruvate is reduced to acetyl-coA, which involves the reduction of pyruvate, the addition of a carbon dioxide from the environment, and its reduction by NADH.
D
Pyruvate is ionized directly to acetyl-coA.
E
Pyruvate is oxidized, and a molecule of carbon dioxide is removed. The electrons removed in this process are used to reduce NAD+ to NADH.

Answer 1

Pyruvate is oxidized and a molecule of carbon dioxide is removed. The electrons removed in this process are used to reduce NAD+ to NADH.

Step-by-step explanation:

In preparing pyruvate to enter the citric acid cycle, the following steps occur:

1. Pyruvate is oxidized, and a molecule of carbon dioxide is removed. The electrons removed in this process are used to reduce NAD+ to NADH.

Answer 2

In preparing pyruvate to enter the citric acid cycle, the step that occurs is pyruvate is reduced, and a molecule of carbon dioxide is removed. The electrons removed in this process are used to oxidize NAD+ to NADH.

Step-by-step explanation:

In preparing pyruvate to enter the citric acid cycle, the step that occurs is:

A. Pyruvate is reduced, and a molecule of carbon dioxide is removed. The electrons removed in this process are used to oxidize NAD+ to NADH.

During the conversion of pyruvate into an acetyl group attached to coenzyme A, a molecule of carbon dioxide and two high-energy electrons are removed. The electrons are picked up by NAD+ and form NADH. This step occurs before the acetyl group can enter the citric acid cycle for further catabolism.