Pyruvate carboxylase catalyzes an anaplerotic reaction that replenishes the TCA cycle. Which statement about this enzyme is correct?

• A It converts pyruvate to acetyl-CoA and requires TPP as cofactor
• B It converts pyruvate to malate and uses NADPH as cofactor
• C It converts pyruvate to oxaloacetate, requires biotin, and is activated by acetyl-CoA ✓
• D It converts pyruvate to oxaloacetate and is inhibited by citrate

Explanation

Pyruvate carboxylase converts pyruvate to oxaloacetate using biotin and ATP. It is allosterically activated by acetyl-CoA, which signals depletion of oxaloacetate. This is the major anaplerotic reaction. Distractor A describes pyruvate dehydrogenase, not pyruvate carboxylase. Distractor D is wrong because acetyl-CoA activates, not inhibits, the enzyme.

Reference: Harper's Illustrated Biochemistry, 32nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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