- Enzymes are biological catalysts. Chemically all enzymes are globular proteins.
- Being proteins, they have colloidal nature and get inactivated during reactions and have to be constantly replaced by synthesis in the body.
- Enzymes are needed only in small quantities for the progress of a reaction.
- Enzymes are very selective and specific for a particular reaction.
- Enzymes lower the energy barrier that reactants must pass over to form the products.
- An enzyme molecule may contain a nonprotein part which is known as prosthetic group.
- For example, the enzyme that catalyses hydrolysis of maltose into glucose is named as maltase.
Mechanism of Enzyme Action
Enzymes are needed only in small quantities for the progress of a reaction. Similar to the action of chemical catalysts, enzymes are said to reduce the magnitude of activation energy.
For example, activation energy for acid hydrolysis of sucrose is 6.22 kJ mol-1, while the activation energy is only 2.15 kJ mol-1 when hydrolysed by the enzyme, sucrase.