Chapter 35, Problem 18A

Summary Introduction

Introduction:

The food when get swallowed from the esophagus it reaches the stomach, but in between the esophagus and stomach, there is a region called the sphincter so the food should cross this region to reach the stomach.

Answer to Problem 18A

Correct answer :

The correct answer is option (A) a low pH and pepsin.

Explanation of Solution

Explanation/justification for the correct answer :

Option (A) a low pH and pepsin. Pepsin is an enzyme produce by the stomach wall that involves the digestion of protein. The enzyme gets activated when the pH of the stomach environment is between the 3.0 to 5.0 range that means low pH should be maintained for the activation of pepsin for protein digestion. So, this is the correct option.

Explanation for incorrect answer :

Option (B) a high pH and bile. If the stomach has a high pH level the acidic environment is not maintained and bile is not involved in the digestion of protein. So, this is an incorrect option.

Option (C) a high pH and pepsin. If the stomach has a high pH level the acidic environment is not maintained and it will not activate the pepsin. So, this is an incorrect answer.

Option (D) a low pH and bile. In low pH, the acidic environment is maintained but bile is not involved in protein digestion. So, this is an incorrect answer.