effect of enzyme concentration on enzyme activity

[champ]

i know that enzyme concentration effects enzyme activity but im not sure exactly how, if anyone can give me a good website where i can find this answer, i would be very greatful. or if anyone can tell me how it is affected. Thx

[Gef]

Strictly speaking enzyme concentration does not affect enzyme activity. The activity of an enzyme molecule depend mainly on ph and temperature and not how many enzyme molecules there are.

However, the rate of a reaction depends on the concentration of enzyme molecules and the concentration of substrate molecules.

[theprof]

In general, the rate of an enzyme-catalysed reaction depends on the concentration of the enzyme and the substrate.

In a typical enzyme concentration, the rate of reaction increases with increasing substrate concentration to a point above which any further increase in substrate concentration produces negligible change in the reaction rate. The reason for this is that the active sites on the enzyme molecules are almost fully saturated with the substrate and no further reaction can occur until dissociation takes place. There is therefore a limit as to how quickly the enzyme can perform its function.

When you increase the enzyme concentration, there are a greater number of enzyme molecules in a given volume. Due to this increase in numbers of molecules, more of the substrate can be converted into the product. As long as the substrate concentration is kept high and the pH and temperature are kept constant, the rate of reaction is proportional to the enzyme concentration.

However, you will eventually reach a point at which there are more enzyme molecules available to accept the substrate than there are substrate molecules. From this point, the enzyme concentration will only make a difference if the substrate concentration is increased.