Problem 99 - Objective Biology for NEET

Question

Optimal \(\mathrm{pH}\) for pepsin is (a) \(6.8\) (b) \(1.8\) (c) \(3.8\) (d) \(6.0\)

Step-by-Step Solution

Answer

The optimal pH for pepsin is 1.8.

Step 1: Understanding Pepsin

Pepsin is one of the primary digestive enzymes in the digestive systems of most animals, including humans. It is active in the stomach, helping to break down proteins into peptides. But, like all enzymes, pepsin works best under specific conditions.

Step 2: Optimal pH for Pepsin

The nature of an enzyme's activity can be affected by changes in pH levels due to the shape of the protein changing. In the case of pepsin, it is most active in highly acidic conditions. It is secreted in an inactive form (pepsinogen) which is activated by the acid in the stomach to become pepsin.

Step 3: The Correct Answer

From the choices given, it can be concluded that pepsin's optimal pH is 1.8 (option b) because this is within the range of the stomach's pH, which is extremely acidic due to the presence of hydrochloric acid. Therefore, the optimal pH for pepsin is 1.8.