Enzyme activity

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aying
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Enzyme activity

Post by aying » Mon Jun 19, 2006 11:24 am

How does 'zero order' reaction relate to the theory of enzyme activity??
Thanks!!

oppox
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Post by oppox » Tue Jun 20, 2006 3:52 pm

The enzyme would be somehow independent of the substrate concentration, well im not so good at this but its maybe like a catalyst, it doesnt speed up the reaction even if u increase the amount.
But I cant really figure out how that reaction would look like when looking at the enzyme.

If u look at a certain kind medicine that is dependent of a enzyme for its distrubution, I guess that is of zero order because even if u increase the amount it doesnt distrubutes more or faster.

Maybe someone else can answer better.

sdekivit
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Post by sdekivit » Fri Jun 23, 2006 4:22 pm

a zero order kinetics is concentration independant and is described by the following equation:

dC/dt = - K

an example of zero order kinetics is the intravenous infusion, where the elimination (say the metabolic elimination in the liver) is independant of the concentration, because you add a drug constanly in the circulation.

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Post by herb386 » Fri Jun 23, 2006 5:02 pm

Enzymes bind to the substrate or substrates before the reaction occurs so the local concentration of substrate is much higher than in solution. This makes the reaction much more like an intramolecular reaction which is a zero order reaction.

Haven't done any chemistry for a while so I could be wrong.

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Post by sdekivit » Mon Jun 26, 2006 8:17 pm

herb386 wrote:Enzymes bind to the substrate or substrates before the reaction occurs so the local concentration of substrate is much higher than in solution. This makes the reaction much more like an intramolecular reaction which is a zero order reaction.

Haven't done any chemistry for a while so I could be wrong.


You know Michaelis Menten-kinetics ?

--> when enzymes are metabolizing at V = Vmax, they metabolize their structure that is not dependant on the concentration of their ligand.

Thus zero-order kinetics is when there is saturation of the enzymes.

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Post by herb386 » Tue Jun 27, 2006 8:17 am

I used to know MM kinetics but had forgotten most of it. Anyway, I looked it up and here is a link that explains it to anyone that cares....

http://www.le.ac.uk/by/teach/biochemweb ... print.html

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