Question

What substance is produced by the oxidation of pyruvate and feeds into the citric acid cycle

• A. pyruvate
• B. glucose
• C. acetyl-CoA
• D. oxygen

Answer 1

The correct option is C acetyl-CoA

Aerobic respiration can be divided into three stages: glycolysis, Krebs cycle and ETC.
At the end of glycolysis, glucose is converted to pyruvate. This pyruvate cannot directly enter the krebs cycle or the citric acid cycle.
Therefore, pyruvate is converted into acetyl-CoA with the help of the enzyme pyruvate dehydrogenase.
The acetyl-CoA thus formed combines with oxaloacetic acid to form citric acid in first step of the krebs cycle.