Question: 153 Given below are two statements:
Statement I: Low temperature preserves the enzyme in a temporarily inactive state whereas high temperature destroys enzymatic activity because proteins are denatured by heat.
Statement II: When the inhibitor closely resembles the substrate in its molecular structure and inhibits the activity of the enzyme, it is known as competitive inhibitor.
In the light of the above statements, choose the correct answer from the options given below:
(1) Statement I is true but Statement II is false.
(2) Statement I is false but Statement II is true.
(3) Both Statement I and Statement II are true.
(4) Both Statement I and Statement II are false.
Answer: Option (3)
Explanation:
Enzymes are proteinaceous in nature and their activity depends on their three-dimensional structure.
At low temperature, enzyme molecules are not denatured but their activity is reduced,
keeping them in a temporarily inactive state.
High temperature causes denaturation of enzymes by disrupting their protein structure,
leading to permanent loss of enzymatic activity.
A competitive inhibitor has a molecular structure similar to the substrate and competes with the substrate for the active site of the enzyme.
Thus, both Statement I and Statement II are correct.