NEDUET Entry Test Biology MCQ
What is the function of the active site of an enzyme?
- (A) It binds with co-factors only.
- (B) It contains a special charged place to fit the substrate.
- (C) It is responsible for the formation of peptide bonds.
- (D) It synthesizes substrates for the enzyme.
Correct Answer: (B) It contains a special charged place to fit the substrate.
Explanation:
The active site is a specific region of an enzyme where the substrate binds.
This region has a unique shape and chemical properties that allow the substrate to fit perfectly.
According to the lock-and-key model, the substrate fits into the enzyme’s active site like a key fits into a lock. This allows the enzyme to catalyze the chemical reaction.
Why other options are incorrect:
- (A) Active site does not bind only cofactors; its main role is binding the substrate.
- (C) Formation of peptide bonds occurs in ribosomes during protein synthesis, not by enzyme active sites in general.
- (D) Enzymes do not synthesize substrates; they only speed up reactions involving substrates.