Page 100 - Color Atlas of Biochemistry

Enzymes 91

A. Uncatalyzed reaction

Reactants Collision Transition Collision Products
complex 1 state complex 2
C
A C
+ D +
B A B D

B. Enzyme-catalyzed reaction

A B

X Y X Y

Z Z

. .
.
2. E A-complex 3. E A B-complex
X Y X Y

Z Active site Z

1. Freeenzyme E 4.Transition state E

X Y X Y

Z Z

. .
.
D 6. E D-complex C C 5. E C D-complex

C. Principles of enzyme catalysis

a Approximation and orientation
of the substrates
Transition
b Exclusion of water state

c Stabilization of the
transition state EA EP
Ea
d Group transfer
Stabilization G
c a c of the EA complex

X Y

b
EA EP
d
Z
Stabilization
of the transition state

Koolman, Color Atlas of Biochemistry, 2nd edition © 2005 Thieme
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