NDA 2 2025 GAT, question 133

Topic: Biology

Q133

The optimum $pH$ at which the enzymes pepsin and trypsin of the human alimentary canal works are

(a) $pH\ 2.0$ and $7.9$ , respectivelyCorrect answer
(b) $pH\ 4.5$ and $3.5$ , respectively
(c) $pH\ 9.5$ and $4.5$ , respectively
(d) $pH\ 7.0$ and $8.0$ , respectively

Solution.

Answer: (a) $pH\ 2.0$ and $7.9$ , respectively

Pepsin acts in the strongly acidic stomach and has an optimum near pH 2.
Trypsin acts in the alkaline small intestine, near pH 8.
The pair 2.0 and 7.9 matches these contrasting environments.