The optimum pH at which the enzymes pepsin and trypsin of the human...

Pepsin is a proteolytic enzyme secreted in the stomach, which requires a highly acidic medium for its optimal activity. The optimum pH for pepsin is around $1\cdot8$ to $2\cdot0$.

Trypsin is a proteolytic enzyme secreted by the pancreas into the small intestine, which requires a slightly alkaline medium for its optimal activity. The optimum pH for trypsin is around $7\cdot8$ to $8\cdot0$.

Therefore, the optimum pH values for pepsin and trypsin are approximately $2\cdot0$ and $7\cdot9$, respectively.

Answer: pH 2·0 and 7·9, respectively