enzymes questions!!!

[JustwantDDS]

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OKay- so this may seem stupid but oh well...

whats the diff btwn non competitve inhibitors and allosteric
i know thats allosteric inhibitors- theres an allosteric site which if the inhibitor binds, theres a conformational change and the substrate cant bind to the active site

but what about non comp?
is it a physical barrier when the inhibitor binds? a conformational change?

 

[casper22]

In non competitive, there are two active site for two different enzymes but binding of one enzyme will block the binding site of the other...

 

[dwelee]

-The Competitive inhibitor:
Bind with the enzyme on the same active site that the substrate usually bind on. In this case, it will compete with the substrate on the active site of the enzyme( decrease the number of the substrates that will bind on the active site by taking their locations).

-The Allosteric inhibitor:
Bind with the enzyme on another site called "Allosteric Site" rather than the active site and causes a conformational change in the enzyme which in turn causes change of the shape of the active site and prevent the substrate from binding with the enzyme.


I hope this is clear 🙂

 

[reztab]

hello my friend. I think I know what made you confuesed, but you are misunderstood one thing allosteric inhibitors are the same as non-competitive ones!!!!!!!! let me explain
In general we have 3 important inhibitors:
Competitve: Binds to the same active site as substrate does and prevents its binding. competitive inhibition can be disrupted by simply adding more subs. therefore it does not change the Vmax but increases the Km value.
Noncompetitive (Allosteric) its binding site is separate from active site and after binding it prevents subs binding to active site by allosteric changes. adding more subs does not do any good.Thus reduces both Km and Vmax.
Uncompetitive (here is your misunderstanding) I know that it looks similar but it is totally different, blieve me it cost me 2 point in my biochem exam.
this one binds to the enzyme -subs complex and causes inactivation. binding site again is separate from active site but it does not cause subs dissosiation. Uncompetitive inhibition does not change Km (i.e., it does not affect substrate binding) but decreases Vmax.
refference: stryer biochemistry
hope it helped