Question
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?
Biology 1 EOC Assessment Sample Questions
A It becomes inactive.
B It begins to replicate.
C Its shape changes to engulf large proteins.
D Its activity increases to digest more proteins.
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?
Biology 1 EOC Assessment Sample Questions
A It becomes inactive.
B It begins to replicate.
C Its shape changes to engulf large proteins.
D Its activity increases to digest more proteins.
Answers
GPT-4o mini
The correct answer is **A: It becomes inactive.**
Pepsin, which is active in the highly acidic environment of the stomach (pH around 2), becomes inactive when it enters the small intestine, where the pH ranges from 7 to 9. The higher pH in the small intestine affects the structure of pepsin, rendering it inactive for protein digestion.
Pepsin, which is active in the highly acidic environment of the stomach (pH around 2), becomes inactive when it enters the small intestine, where the pH ranges from 7 to 9. The higher pH in the small intestine affects the structure of pepsin, rendering it inactive for protein digestion.