Which one of the following compound(s) is/are NOT the carbon source of acetyl Co-A?
Which one of the following compound(s) is/are NOT the carbon source of acetyl Co-A?
Select an option to attempt
Correct Answer: Option D
Explanation
Carbon sources for Acetyl-CoA:Acetyl-CoA can be generated from:• Ethanol → Acetaldehyde → Acetate → Acetyl-CoA• Pyruvate → Acetyl-CoA (via pyruvate dehydrogenase complex; losing one CO₂)• Valine and Isoleucine (branched-chain amino acids): partially ketogenic, catabolised to propionyl-CoA and acetyl-CoA• Acetoacetate (a ketone body): converted to 2 Acetyl-CoA via thiolaseNOT a carbon source for Acetyl-CoA:• Oxaloacetate (OAA): a 4-carbon TCA cycle intermediate that is glucogenic — it CANNOT be converted to Acetyl-CoA (no enzyme catalyses OAA → Acetyl-CoA directly).Answer: Oxaloacetate/acetoacetate (Option 4) — specifically oxaloacetate is the one NOT a carbon source.