Question

Which of the following statement(s) about enzyme is/are correct?

• A. Enzymes are non-specific.
• B. Enzymes are temperature and pH specific
• C. Almost all enzymes are proteins
• D. Enzymes act as catalyst

Answer 1

Answer: (B), (C), (D)

Enzymes act as catalyst

Characteristics of Enzyme:
1. Most highly efficient
One molecule of an enzyme may transform one million molecules of the reactant per minute

2. 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.

3. 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.

4. Highly active under optimum pH
The rate of an enzyme-catalysed reaction is maximum at a particular pH known as optimum pH

5. Influence of activators (Generally metal ions , example :Amylase in presence of sodium chloride i.e., $N{a}^{+}$ ions)

They are weakly bonded to enzyme molecules and increase the catalytic activity.

6. Influence of inhibitors and poisons
The inhibitors or poisons interact with the active functional groups on the enzyme surface.They often reduce or
completely destroy the catalytic activity of the enzymes.