Carnitine Shuttle | Purpose and Mechanism

The video explains the role of carnitine in fatty acid metabolism, focusing on its importance in transporting long-chain fatty acids into the mitochondria for beta oxidation. It details the carnitine shuttle mechanism, highlighting the impermeability of the mitochondrial membrane to long-chain fatty acids and the role of enzymes like CPT1 and CPT2. The process of beta oxidation and the recycling of carnitine are also covered, along with the regeneration of carnitine into acetylcarnitine. The video concludes with a summary and encourages viewers to like and subscribe.

Why is carnitine essential in fatty acid metabolism?

• It breaks down fatty acids in the cytosol.

• It transports long-chain fatty acids into the mitochondria.

• It helps in the synthesis of fatty acids.

• It converts fatty acids into glucose.

What is the primary reason for the carnitine shuttle?

• To synthesize carnitine in the mitochondria.

• To convert fatty acids into proteins.

• To transport short-chain fatty acids across the membrane.

• To allow long-chain fatty acids to enter the mitochondria.

Which enzyme is responsible for activating long-chain fatty acids at the outer mitochondrial membrane?

• Carnitine acetyltransferase

• CPT1

• Acyl-CoA synthetase

• CPT2

What role does CPT1 play in the carnitine shuttle?

• It transports fatty acids into the cytosol.

• It adds carnitine to fatty acyl-CoA.

• It removes carnitine from fatty acylcarnitine.

• It adds a coenzyme A to fatty acids.

How does fatty acylcarnitine cross the inner mitochondrial membrane?

• Through a sodium-dependent transporter.

• By active transport using ATP.

• Via the carnitine acylcarnitine translocase.

• Through simple diffusion.

What is the function of CPT2 in the mitochondrial matrix?

• It synthesizes new carnitine molecules.

• It adds carnitine to fatty acyl-CoA.

• It removes coenzyme A from fatty acids.

• It converts fatty acylcarnitine back to fatty acyl-CoA.

How is carnitine recycled back to the cytosol?

• Via passive diffusion across the membrane.

• By binding to acetyl-CoA.

• Through the carnitine acylcarnitine translocase.

• By converting it into glucose.