Which of the Following Best Describes Carnitine

Question

Which of the following best describes carnitine?
A) It transports fatty acids across the inner mitochondrial membrane for breakdown.
B) It transports acetyl-CoA to the cytosol for fatty acid synthesis.
C) It's a precursor of cholesterol.
D) It carries growing acyl chains during fatty acid synthesis.
E) none of these

Accepted Answer

Carnitine is a molecule that plays a crucial role in transporting fatty acids from the cytoplasm into the mitochondria, where they can be broken down for energy. The transport of fatty acids across the inner mitochondrial membrane is the main function of carnitine. Choice B is incorrect because acetyl-CoA is not transported to the cytosol for fatty acid synthesis; instead, it is used as a substrate for fatty acid synthesis in the cytosol. Choice C is incorrect because carnitine is not a precursor of cholesterol. Choice D is incorrect because growing acyl chains during fatty acid synthesis are carried by acyl carrier protein (ACP), not carnitine.