Re: how does enzyme concentration affect enzyme activity and what is it?

Hello,

Your hypothesis is true!  You are right about all of your factors and it is 
an interesting thing to study.

Enzyme concentration does not alter the enzyme activity per se 
though.  Enzyme concentration affects the rate of the reaction.  In optimal 
conditions, if you double the concentration of enzyme, you should double 
the speed at which the reaction occurs.  

As "ideal conditions" and "reality" are two very different things, you can 
guess that this is not always the case.  Impurities in the reaction buffer 
that inactivate the enzyme could affect the speed of the reaction at low 
enzyme concentration but this effect would disappear at high concentration 
of enzyme.  Dilution of enzyme could also reduce the speed of the reaction 
if the enzyme needs a critical cofactor or if the enzyme only works when 
grouped together (quaternary structure).  Opposite to this, the rate could 
be higher at low concentration of enzyme if an inhibitor is present in the 
preparation of enzyme or if the enzyme aggregate at high concentration and 
gives a lesser active enzyme.

In the end, enzyme concentration does affect the rate of a reaction (ie. 
the speed at which the reaction occurs) but enzyme activity is not affected 
by it under ideal conditions...

I hope it answered your question,

Ciao!

Mike