Figure 8.5 The carrier functions of coenzymes.
Many enzymes use coenzymes to transfer chemical groups from one
substrate to another.
(c)
Products
E
Figure 8.4 Enzymesubstrate
reactions.
(a) When the enzyme and
substrate come together, the
substrate (S) must show the correct
fit and position with respect to the
enzyme (E). (b) When the ES
complex is formed, it enters a
transition state. During this
temporary but tight interlocking
union, the enzyme participates
directly in breaking or making
bonds. (c) Once the reaction is
complete, the enzyme releases the
products. (d) The induced-fit
model proposes that the enzyme
recognizes its substrate and adapts
slightly to it so that the final
binding is even more precise.
E
(a) (b)
Substrate (S)
Does
not fit
Enzyme (E) ES complex
(d)
S
E E
8.1 The Metabolism of Microbes 221