766 / 912
758 Chapter 23
Copyright © 2017 Pearson Education, Inc.
Solutions to Problems
1.
The metal ion
(Zn
2
+
)
makes the carbonyl carbon more susceptible to nucleophilic addition, increases the
nucleophilicity of water by making it more like a hydroxide ion, and stabilizes the negative charge on the
transition state.
2.
The alcohol is oxidized to a ketone.
_
O
O
O
O O
OH
O
_
_
+
NAD
+
+
isocitrate
dehydrogenase
_
O
O
O
O O
O
O
_
_
+
NADH H
+
3.
The ketone is reduced to an alcohol.
_
+
+
NADH H
+
+
NAD
+
O
O
O
_
O
O
OH
enzyme
4.
a.
FAD has seven conjugated double bonds (indicated by *).
N
N
NH
N
H
3
C
H
3
C
O
R
*
*
*
*
* *
*
O
b.
FADH
2
has three conjugated double bonds (on the left of the molecule). It also has two conjugated
double bonds (on the right of the molecule) that are isolated from the other three.
N
H
N
NH
H
N
H
3
C
H
3
C
O
R
*
*
*
*
*
O