Enzymes are mostly proteins. They function as catalysts in biochemical reactions by lowering the energy of activation.
Characteristics of Enzyme:
1. Highly specific nature
Each enzyme is specific for a given reaction.One catalyst cannot catalyse more than one reaction. Example: The enzyme urease catalyses the hydrolysis of urea only.It does not catalyse hydrolysis of any other amide.
2. Highly active under optimum temperature
The rate of an enzyme reaction becomes maximum at a definite temperature known as optimum temperature.On either side of the optimum temperature, the enzyme activity decreases.
3. Highly active under optimum pH
The rate of an enzyme-catalysed reaction is maximum at a particular pH known as optimum pH
Hence, option (b) is correct.