Environmental effects on enzyme activity

As well as inhibitors and activators, enzymes are affected by various environmental effects, of which the most important are pH and temperature. 

In this equation k represents some kinetic constant for the reaction, such as the catalytic constant or the specificity constant, k is a notional pH-independent 

We may erqrect both the free enzyme and all intermediate complexes that occur in an enzyme-catatysed reaction to exist in multiple states of protonation, and so we can expect any parameter of the reaction to vary with pH. In general the pH dependence of the specificity constant Jja or ko/Km provides information about the protonation states of the free enzyme, and that of the catalytic constant ko, provides information about the protonation states of the enzyme-substrate complex(es). The pH dependence offCn, is usually more complicated, as it involves contributions from all of the different forms of enz)mie it is most easily analysed by regarding as ko/(fco/Km)- 

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