Question

1. as food travels through the digestive system, it is exposed to a variety of ph levels. the stomach has a ph of 2 due to the presence of hydrochloric acid (hcl), and the small intestine has a ph ranging from 7 to 9. hcl converts pepsinogen into pepsin, an enzyme that digests proteins in the stomach. which of the following most likely happens to pepsin as it enters the small intestine? a. it becomes inactive. b. it begins to replicate. c. it’s shape changes to engulf large proteins. d. it’s activity increases to digest more proteins.

Explanation:

Enzymes like pepsin have an optimal pH for activity. Pepsin works best in the acidic (pH 2) stomach environment. The small - intestine's pH (7 - 9) is alkaline, which is not its optimal pH, so it becomes inactive.

Answer:

A. It becomes inactive.