Question

Which of the following intermediary metabolites enters the Krebs cycle and is formed, in part, by the removal of CO2 from a molecule of pyruvate?
A) lactate
B) glyceraldehyde phosphate
C) oxaloacetic acid
D) acetyl CoA
E) citric acid

Answer 1

Answer:

The correct answer will be option-D.

Explanation:

Before Citric acid cycle or Krebs cycle, an intermediate reaction takes place which converts the pyruvate into Acetyl CoA. This reaction is known as pyruvate decarboxylation as it produces Carbon dioxide.  

Coenzyme A reacts with pyruvate which causes the release of two oxygen atoms and one carbon to form CO₂ along with the reduction of  NAD+ to NADH and produce "Acetyl CoA."

Thus,  option-D is the correct answer.