16/10/23
BIO
Enzymes continued
Non-competitive
Inhibition
the
:
Inhibitor does not compete with
the Inhibitor does not have a similar
Non-competitive reversible
Three types
:
2
Non-competitive Irreversible
3
AllOSterIC
the substrate for the active site of the enzyme
.
shape to the substrate
Non-competitive reversible inhibition :
the Inhibitor binds to a site other than the active site so the active site
causes a conformational
How ?
from occurring
.
change
is
still available for the substrate to
higher concentration of
Inhibitors the higher the binding of Inhibitors
takes the place and binds
saturation of Inhibitors
to enzymes decreasing the rate of reaction since more Inhibitors
max
will
(See fig
.
.
1.
0) so
one detaches another Immediately
more Inhibitors , more prevention of Catalysis products , slower rate of ran
,
.
bombardment of the enzymes by Inhibitors to the point where the reaction rate Is almost still with no
:
catalysts
products since
and thus
.
,
bind to an/ the enzyme so the shape of the enzyme would continue changing and as
can
bind to
the enzyme but does not prevent the substrate from binding It does however prevent catalysis
It shifts the enzyme's position in a way such that the R groups are moved / shifted
in
to the formation of products so with nearly no
Is directly linked
never
catalysts , there is
nearly no
products
be achleved
-
Ratot
RT
~
no
Inhibitor
no
inhibitor
inhibitor
in
with
~max
-
competitive
Inhibition
substrate concen
1
,
8
substrate concentrat
.
Non-competitive Inhibition decreases the
factor, so changing that
f 19
to
Umax despite an increase in
substrate because
.
reversine
Inhibition
.
competition for the active site
concentration does not affect the fact that these Inhibitors prevent catalysis and
non-COMP
Is not the
limiting
binds to another site
from the active site
Umax without the
lower as well
2
Inhibitor Will never be actually achleved and will continue to get lower and lower and such the graph will get
of the curve
with regards to the shape
End
Heavy metals :
Non-competitive Irreversible
·
arsenic-Sllv
-
Inhibitor binds permanently to enzyme
-
-
can bind in different ways :
1
:
heavy metals
may
be
Organophosphates
-
:
group of the amino add cysteine this
↳ the Only 1
.
its
tertiary structure
Irreversibly and
permanently binds to neurotransmitter of acetylcholine
2
( SH)
miner
active site or elsewhere
they denature the enzyme by changing
:
er
↑
lodine containing compounds can bind permanently with the sulhydry
and
in the
mercury
lead
site will
the active
receptor
be unable to bind with its substrate
affecting the respiratory
it
permanently binds to the receptor preventing the diffusion
of chemicals In impulses so permanent contraction of relative
muscles
thus
Pre synaptic
active Ingredient
-
acetylcholine
disulfiram
:
When alcohol Is absorbed In the body ,
an
It
Is
converted I broken down into
aldehyde by a specific enzyme (alcohol
dehydrogenase
neurotransmitters
denydronase
so It causes the
thereby preventing ethanal to be
broken down into ethanolc acd
causing the symptoms of hangover
-in a nes e
binding
receptor for
ethanoic acld
Inhibits ethanal dehydrogenase
.
accumulation of ethanal
,
which is
⑧
Inhibitor permanently
hydrogenase)
ethanolol e ethanal-->
ethanal
Impulses
neuron
preventing the muscles from functioning
neurotransmitter
Antabuse
P
System
cause Paralysis as
⑧
S
↳
V
C
O
diffusion of
m
w
I
chemicals
POSA SynaPHC
poisonous
/
.
neuron
16/10/23
3
Allosteric Inhibitors :
↳
Recent binds
binding of the
to
allosteric site , similarl to that
Inhibitor causes a conformational
It Changes the active site
in
non-competitive reversible inhibition
to
active
site
,
Since
.
Allosteric
We
rate
·
5
W
substrate
vs
.
Non-comp
binds to allosteric
·
Site
·
changes active site
·
Reversible
.
bindstoanyOthere
does not change active
SIC
enzyme
5
.
change which prevents the substrate from
binding
·
prevents substrate
does
·
from binding
·
not
prevent
substrate from binding
reversible
·
reversible
allosteric->
Site
enzyme
W
allostere
Inhibitor
How are allosteric Inhibitors
allosteric Inhibitors
in
·
are
I
enzyme
used
?
often used
In end product
Inhibition also known as
negative feedback Inhibition
metabolic pathways
end products of metabolic pathways can bind to enzymes along the
metabolic pathway to prevent
so as the concentration of those products Increases and thus they accumulate , they
,
enzymes present so no more products can be formed until the concentration of the
In that
case, the products unbind from the enzymes so
overproduction and wastage of cellular energy
.
more products can be
overproduction and wastage of cellular energy
regulate the metabolic pathway by temporarily binding to the
products decreases to a neutral
state
where they are
needed again
.
formed and the process can continue which prevents accumulation
,