Explain factor affecting enzyme activity.

Hint: Enzymes are known as biological catalysts since it catalyzes a wide range of biological reactions converting substrates into products inside the cells and like catalysts itself remains unchanged at the end of the reaction.

Complete Answer:
- Enzymes are globular proteins that either act alone or in large complexes. Only a small region of their large structure is involved in carrying out the catalysis. This region consists both of the catalytic site where catalysis takes place and binding site where the substrate binds, these two sites together make up the active site of the enzyme.
- The binding of substrates to enzyme’s active site is highly specific, the specificity is due to the presence of certain specific amino acid residues that are found at the active site. The binding of enzymes to substrates is demonstrated by two models- lock and key model and induced fit model.
- The enzyme being a protein is affected by several factors such as temperature, pH , substrate concentration and presence or absence of activator or inhibitor. With increase in temperature to a certain limit the enzyme activity increases after which with further increase the activity decreases.
- Each enzyme has an optimal pH range at which its activity is maximum, any increase or decrease from that pH affects the activity of enzymes. With increase in substrate concentration the enzyme activity increases but the activity reaches a constant when all the active sites are occupied by substrates.
- In presence of an activator the enzyme activity increases whereas in presence of an inhibitor the enzyme activity decreases, activators and inhibitors bind to a site other than the active site.

Note: Enzymes have a wide range of biological functions, they are involved in metabolic reactions, post translational modifications as well as in development of certain diseases. Enzymes are also used in industries such as biofuel industry, detergent industry, brewing industry, etc.