Question

Pepsin is produced by cells lining the stomach. It catalyzes reactions needed to digest certain proteins. After leaving the stomach, food enters the small intestine. The pH of the small intestine is around 7. What would most likely happen to pepsin enzymes that traveled with the food from the stomach to the small intestines?

Answer 1

The optimum pH for Pepsin should be around 2.0, which is what the stomach pH is. When it travels to somewhere with pH 7, the Pepsin enzyme should be denatured, due to the extreme pH.

Answer 2

irreversible denaturation

Step-by-step explanation:

Pepsin is a monomeric protein with two domains with a beta barrel architecture. The active enzyme site contains two aspartate residues. To activate, one of these aspartate residues must be protonic, while the other must be deprotonated. This occurs between the acidic pH (pH 1-5) provided by the HCl in the gastric juice. This is how the transition from pepsinogen to active pepsin occurs. However, above pH 7, pepsin irreversibly denatures.