Pyruvate carboxylase catalyzes the first committed step of gluconeogenesis. Which statements about it are correct? It requires biotin as a prosthetic group, it is located in the mitochondrial matrix, and it is allosterically activated by:

• A Fructose-2,6-bisphosphate
• B Citrate
• C AMP
• D Acetyl-CoA ✓

Explanation

Pyruvate carboxylase is a mitochondrial, biotin-dependent enzyme that converts pyruvate to oxaloacetate using CO2 and ATP. It is allosterically activated by acetyl-CoA, ensuring that when fatty acid oxidation supplies abundant acetyl-CoA and energy, pyruvate is diverted into gluconeogenesis rather than being oxidized by pyruvate dehydrogenase. AMP inhibits gluconeogenic flux further downstream, and citrate signals toward lipogenesis.

Reference: Lippincott Illustrated Reviews: Biochemistry, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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