Question

Describe the important properties of enzymes.

Answer 1

Hint: Enzymes are the proteins that catalyze the biochemical reactions in the living cells, hence also called Biocatalyst.

Complete answer:
Properties of enzymes are:
Protein nature: Enzymes are generally proteins. They may have additional inorganic or organic substances for their activity.
Chemical reaction: Enzymes do not start a chemical reaction but increase the rate for a chemical reaction. They do not change the equilibrium but bring about equilibrium very soon.
Efficiency: The number of molecules of the substrate that an enzyme can change per minute is called the turnover number. An enzyme with a higher turn over number is more efficient.
Unchanged form: Enzymes are no way transformed or used up in the chemical reaction but come out unchanged at the end of the reaction.
Enzymes Specificity: Enzymes are highly specific in their action.
Factors affecting enzyme activity:
The temperature at which the enzyme shows its highest activity is known as its optimum temperature. Enzyme activity decreases both below and above the optimum temperature.
Hydrogen ion concentration (pH): Every enzyme has an optimum pH when it's more effective to rise or fall in pH reduces enzyme activity.
- The concentration of substrate: Increase in substrate concentration, increases the velocity of the enzymatic reaction. The reaction ultimately reaches a maximum velocity (V_max) which is not exceeded by any further rise in the concentration of the substrate. This is because, at this stage, the enzyme molecules become fully saturated and no active site is left free to bind additional substrate molecules.
- K_m (Michaelis constant) is a mathematical derivation or constant which indicates the substrate concentration at which the chemical reaction catalyzed by an enzyme attains half its maximum velocity.

Note:
- The mechanism of enzyme action explained by two hypotheses, the Lock and key hypothesis (most acceptable) and the Induced fit hypothesis.
- Allosteric enzymes do not show typical Michaelis constants.
- An enzyme has an active site where the substrate binds. It is highly specific.