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766 Chapter 23
Copyright © 2017 Pearson Education, Inc.
26.
a.
acetyl-CoA carboxylase; biotin
b.
dihydrolipoyl dehydrogenase; FAD
c.
methylmalonyl-CoA mutase; coenzyme
B
12
d.
aspartate transaminase; pyridoxal phosphate
e.
propionyl-CoA carboxylase; biotin
27.
a.
thiamine pyrophosphate, lipoate, coenzyme
A, FAD, NAD
+
,
indicated by numbers 1–5 in the
mechanism below
b.
The mechanism is exactly the same as that for the pyruvate dehydrogenase system.
H B
−
-keto-
glutarate
thiamine pyrophosphate
H B
lipoate
+
CO
2
2
1
−
CoASH
3
HS SH
+
FAD
4
+
FADH
2
NAD
+
5
FAD
+
NADH
+
H
+
_
_
C
O
O
C
OH
_
C
OH
CH
2
CH
2
C
O
CH
2
CH
2
O
C
O
_
CH
2
CH
2
O
C
O
_
O
_
CH
2
CH
2
O
C
O
C
O
C
O
C
O
succinyl-CoA
SCoA
_
CH
2
CH
2
O
C
O C
O
O
OH
B
−
C
_
CH
2
CH
2
O
C
O
S
C
RN
+
S
C
RN
+
S S
R
S SH
S
C
RN
+
S
C
RN
+
S
C
RN
R
S SH
R
S S
R
R