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760 Chapter 23
Copyright © 2017 Pearson Education, Inc.
8.
CH
3
C
HO
H
2
C
CO
R
_
C
O
O
_
C
O
O
S
C
RN
+
pyruvate-TPP
intermediate
a -keto acid
9.
Notice that the only difference in the mechanisms for pyruvate decarboxylase and acetolactate synthase is
the species to which the two-carbon fragment is transferred—a proton in the case of pyruvate carboxylase
and pyruvate in the case of acetolactate synthase.
S
C
−
RN
H B
+
CH
3
C
HO
CH
3
C
HO
H B
+
CO
2
CH
3
C
O
C
OH
CH
3
H B
_
+
acetolactate
−
−
O
O
_
_
C
O
O
O
_
_
C
O
C CH
3
C
O
C CH
3
C
HO CH
3
C
O
O
S
C
RN
+
S
C
RN
S
C
RN
+
S
C
RN
+
O
CH
3
C
O
O
C
O