試題詳解

46. Which of the following statements concerning the biosynthesis of fatty acids is false?
(A) Fatty acid synthesis occurs in the cytosol of many organisms but in the chloroplasts of plants.
(B) Biosynthesis of fatty acids requires the participation of a three-catbon intermediate, malony1-Co A, which is formed via the reaction catalyzed by acetyl-CoA carboxylase.
(C) In nonphotosynthetic eukaryotes, nearly all the acetyl-CoA used in fatty acid synthesis is formed in mitochondria, and the acetyl group used in fatty acid synthesis is shuttled out of mitochondria as citrate.
(D) If malonyl-CoA is synthesized from ¹⁴CO₂ and unlabeled acetyl-CoA, and the labeled product is then used for fatty acid synthesis, the final product (fatty acid) will have radioactive carbon in every even-numbered C-atom.
(E) Fatty acid biosynthesis uses NADPH exclusively, whereas oxidation uses NAD⁺ exclusively.