Competitive
Inhibition
Inhibitors
are
compounds
that
decrease
an
enzymes
activity
competes
with
substrate
for
binding
Irreversible
inhibitors
Cin
activators
)
react
with
enzyme
Binds
active
site
One
inhibitor
molecule
can
permanently
shut
off
one
enzyme
molecule
Does
not
affect
catalysis
Often
powerful
toxins
;
can
also
be
used
as
drugs
=
(
÷?)É]+Émax
Reversible
Inhibitors
bind
-10
and
can
dissociate
from
enzyme
a.
=z↑CI
]
No
change
In
Vmax
;
apparent
Increase
in
14M
Line
Weaver
-
Burk
:
lines
intersect
at
they
-
axis
often
structural
analogs
of
substrates
or
products
-
1-
-
c-
+
s
-
Es
-
up
No
inhibitor
Often
used
as
drugs
to
slow
down
a
specific
enzyme
+
cÉmᵗm
)
I
⑤
can
bind
-10
:
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.
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free
enzyme
/
prevents
binding
of
the
substrate
El
Enzyme
substrate
complex
/
prevents
reaction
Un
-
Competitive
Inhibition
Ets
←
Es
→
El-P
Lb+É¥
+
,
only
binds
to
ES
complex
%
:
¥
→
Est
9
/
①
(UH
Does
not
affect
substrate
binding
and
Inhibits
catalytic
function
Decrease
in
Vmax
;
apparent
decrease
in
kna
No
change
in
km
/
Vmax
Non
-
Competitive
Inhibition
É◦=GY÷*)És]+Éma×
i
Line
Weaver
-
Burk
;
lines
are
parallel
Binds
enzyme
with
or
without
substrate
s
Enzyme
Allosteric
Regulation
Binds
-10
regulatory
site
canister
'd
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Binding
of
a
molecule
to
a
different
location
from
active
site
causes
changes
in
Inhibits
both
substrate
binding
/
catalysis
enzymatic
activity
;
either
4)
orcs
,
(4)
or
(
↓
)
activity
of
enzyme
Decrease
in
Vmax
;
apparent
change
In
Km
Allosteric
Inhibition
→
binding
of
a
molecule
to
allosteric
site
causes
a
shape
change
that
reduces
the
affinity
of
the
enzyme
for
the
substrate
Line
Weaver
-
Burk
:
lines
intersect
left
from
the
y
axis
Allosteric
activator
→
conformational
change
that
(4)
affinity
Noncompetitive
inhibitors
are
mixed
inhibitors
;
no
change
in
km
of
an
enzyme
for
the
substrate
④
inhibitor
⑧0
(
t
)
modulator
Enzyme
Non
-
Competitive
Competitive
Inhibition
End
product
inhibition
☒
Substrate
Rtd
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substrate
inhibitor
substrate
enzyme
substrate
Inhibitor
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substrate
binding
binding
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iq
site
site
site
binding
Less
active
enzyme
INHIBITOR
substrate
Allosteric
Ste
The
inhibitor
binding
→
-
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and
substrate
site
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Ggg
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binding
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reaction
fits
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More
active
enzyme
⑥
enzyme
undergoing
binding
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,
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,
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,
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by
inhibition
end
product
Inhibitor
binds
[
1%4
to
enzyme
;
substrate
reaction
IS
g|
⑨
Binding
of
↓
not
carried
instead
Of
too
much
end
product
inhibitor
causes
◦
"
+
:(
"
°
Inhibitor
.
_
excess
binds
to
the
substrate
binding
site
①
substrate
chemical
ward
to
change
shape
:
without
inhibitor
can
bind
)
reaction
Is
allosteric
site
:
changes
carried
out
/
the
shape
of
the
substrate
causes
chemical
end
product
bind
site
;
substrate
complex
not
carried
out
reaction
-10
be
carried
produced
no
longer
binds
;
stops
out
/
product
produced
metabolic
pathway
"
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state
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Allosteric
Regulation
kinetics
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