The carnitine shuttle system transports long-chain fatty acyl-CoA into the mitochondrial matrix for beta-oxidation. Which component of this system is located on the inner mitochondrial membrane and catalyzes the transfer of the fatty acyl group back to CoA?

• A Carnitine palmitoyltransferase I
• B Acyl-CoA synthetase
• C Carnitine-acylcarnitine translocase
• D Carnitine palmitoyltransferase II ✓

Explanation

CPT-II is located on the inner mitochondrial membrane and converts acylcarnitine back to acyl-CoA inside the matrix. CPT-I is on the outer mitochondrial membrane and is inhibited by malonyl-CoA. Carnitine-acylcarnitine translocase exchanges acylcarnitine for free carnitine across the inner membrane. Acyl-CoA synthetase activates fatty acids on the outer mitochondrial membrane prior to carnitine conjugation.

Reference: Lehninger Principles of Biochemistry, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.