Factors affecting Enzyme Activity

How does temperature affect enzyme activity?

Initially, as the temperature increases, the rate of enzyme activity increases. This is because higher the temperature, greater the kinetic energy, therefore greater chance of collision between the enzyme and substrate molecules. Thus higher rate of reactions.

At the optimum, the enzyme works the best. That is the highest rate of reaction.

Beyond the optimum, the shape of the active site changes (denatured). The substrate will no longer fit into the active site. The rate of reaction decreases.

how does pH affect enzyme activity

At extreme lower and higher pH, the enzyme’s active site shape changes. It gets denatured so the rate of reaction is low. It is at its highest at the optimum pH.

how does enzyme concentration affect enzyme activity

Initially, as the enzyme concentration increases, the rate of reaction increases, after which the rate remains constant because there are no more substrate to fill the active site.

how does substrate concentration affect enzyme activity

Initially, as the substrate concentration increases, the rate of reaction increases as there are free active sites. More enzyme-substrate complexes are formed.

The rate then becomes constant because there are no more enzyme active sites.