試題詳解

43. Fatty acid synthesis and degradation are reciprocal processes. Which of the following statements regarding their chemical distinction is      NOT      correct?
(A) In degradation, the fatty acyl group is esterified to the thiol group of coenzyme A, whereas in biosynthesis, the growing chain is attached to the thiol group ofthe ACP domain of fatty acid synthase.
(B) Coenzyme A carries acyl units between different multi-enzyme complexes, while ACP shuttles intermediates between the active sites of a single enzyme complex.
(C) The 4'-phosphopantetheine group in CoA is linked to a 3'-phospho-adenosine diphosphate, while in ACP, the same prosthetic group is linked to a highly conserved serine residue of the protein.
(D) During synthesis, the initial priming requires the transfer of an acetyl group from CoA to the ACP, followed by a transfer to a cysteine residue on the ketoacyl synthase domain.
(E) The hydroxyacyl intermediate in the biosynthetic pathway is the L-stereoisomer, mirroring the L-stereoisomer found in the B-oxidation pathway to maintain enzymatic compatibility.