FACTORS AFFECTING ENZYME ACTIVITY

There is an optimum temperature at which enzymes function best – generally around 40 degrees

But why the gradual build and drop off?

TEMPERATURE

Normal body temp is around 37 degrees

Above that temperature and the proteins that make up the enzyme begin to denature i.e. break down

Below that temp and the molecules are not moving at an optimum speed for the reaction to take place!

TEMPERATURE

pH (or the scale of acidity) also has a bell shaped curve

In highly acidic or basic environments enzymes do not function as well

PH

The optimum pH is around 8

Any more basic or acidic and enzymes can be broken down or denatured and begin to loose their function.

PH

The substrate (in our lab the H2O2) can vary within the body/cell based on a number of conditions

This will cause an increase in enzyme activity…. To a point!

SUBSTRATE CONCENTRATION

At some point, which will vary based on the other factors, the rate of reaction will not increase any further.

All of the enzymes are saturated or being used.

SUBSTRATE CONCENTRATION

As the enzyme concentration increases the rate of reaction increases.

This is true provided there are enough substrate molecules to continue to react with.

ENZYME CONCENTRATION

For instance, if there was always enough peroxide to react with, adding more catalase would increase the rate of reaction indefinitely

ENZYME CONCENTATION