試題詳解

80. In bacteria, the biosynthetic routes for proline and arginine diverge when glutamate is N-acetylated for arginine synthesis. Which of the following explains why acetylation is required for arginine synthesis but not proline synthesis?
(A) Acetylation alters the pK_a of the amine group.
(B) Acetylation prevents reduction of the amine group in N-acetylglutamate-δ-semialdehyde.
(C) Acetylation activates tiie amine group for synthesis of the guanidine group of arginine.
(D) Acetylation prevents the cyclization of N-acetylglutamate-δ-semialdehyde.
(E) None of the above.