FACTORS AFFECTING ENZYME ACTIVITY

1. Substrate concentration.
If the concentration of the substrate is increased while that of the enzyme remains constant, the rate of the reaction will increase for some time and then becomes constant. Any further increase in substrate concentration will result in a corresponding increase in the rate of the reaction.

2. Enzyme concentration.
The rate of an enzyme controlled reactions increases as the enzyme concentration increases as long as no other factors are limiting as shown above,

3. Temperature of the medium.
The rate of an enzyme- catalyzed reaction increases with temperature up to a maximum, called the optimum temperature.
Most enzymes work best (optimum temperature) between 30c-40c. Like all proteins enzymes are denatured when heated over 60c. They are in activated by low temperatures (0c and below).

4. PH.
Every enzyme has a particular PH range over which it works best. Some enzymes work best in acidic medium while others function best in alkaline medium.
Example.
Pepsin has its optimum PH at 2.2 while trypsin has its optimum PH of around 7-8 as shown below.

5. The presence of inhibitors. (These are small molecules).
They reduce the enzyme activity. They make the enzyme deformed rendering it useless hence lowering the rate of enzyme action.
6. Presence of activators.
These are mainly;
• Cofactors
• Coenzymes.
Cofactors are non protein compound, which promote efficiency activity e.g. Zn, Fe, Cu, etc.
Coenzymes are organic non- protein molecules which promote efficiency action of enzymes.