Figure 2.

L-Carnitine functions as a cofactor for long-chain fatty acids across the inner mitochondrial membrane. Fatty acids rely on a set of proteins, including transport proteins, to enter the cell. Once inside, long-chain fatty acids bind to CoA to form acyl-CoA. However, the impermeability of the mitochondrial membrane to acyl-CoA requires the involvement of L-Carnitine as a shuttle for the transport of fatty acids into the mitochondria. OCTN2 facilitates the transport of L-Carnitine into the cell. Subsequently, CPT I enables the transfer of the acyl group from acyl-CoA to carnitine, forming acyl-carnitine. CACT then translocates acyl-carnitine across the inner mitochondrial membrane. Once inside the mitochondria, CPT II cleaves acyl-carnitine, releasing the acyl group, which subsequently binds to CoA, initiating β-oxidation. Upon completion of this process, carnitine is transported back to the cytoplasm through the CACT, allowing for its reuse in subsequent cycles. This intricate transport mechanism involving L-Carnitine is essential for the efficient utilization of fatty acids as an energy source within the mitochondria. It ensures the proper delivery of fatty acids to the site of β-oxidation, facilitating their effective metabolism and energy production.