80.tIn 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)tAcetylation alters the pKa of the amine group.
(B)tAcetylation prevents reduction of the amine group in N-acetylglutamate-δ-semialdehyde.
(C)tAcetylation activates tiie amine group for synthesis of the guanidine group of arginine.
(D)tAcetylation prevents the cyclization of N-acetylglutamate-δ-semialdehyde.
(E)tNone of the above.