Acetyl-CoA for cytosolic fatty acid synthesis is generated in mitochondria from pyruvate oxidation. Which carrier transports this carbon into the cytosol across the inner mitochondrial membrane?

• A Oxaloacetate
• B Acetylcarnitine
• C Malonyl-CoA
• D Citrate ✓

Explanation

When mitochondrial ATP and citrate levels are high, citrate is exported through the tricarboxylate transporter into the cytosol, where ATP citrate lyase cleaves it back to acetyl-CoA and oxaloacetate. This citrate shuttle links the fed state to lipogenesis. Acetylcarnitine does not carry carbon for fatty acid synthesis, malonyl-CoA is formed after cytosolic entry, and oxaloacetate cannot cross the inner membrane directly.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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