Question

What is the role of bile salts in the mammalian digestive system?

• A. Bile salts convert pepsinogen to pepsin, and thus facilitate protein digestion
• B. Bile salts emulsify fat, and thus aid in fat digestion
• C. Bile salts are excretory products produced by the liver, and do not participate in digestion
• D. Bile salts facilitate digestion of all types of macromolecules in the small intestine

Hint:

Bile salts are {emulsifiers}, not enzymes. They make fat droplets accessible to pancreatic lipase for efficient digestion.

Answer 1

The Correct Option is B

Step 1: Recall the function of bile salts.
Bile salts are amphipathic molecules synthesized in the liver from cholesterol and secreted into the intestine via bile.
Step 2: Mechanism of action.
They emulsify large fat globules into smaller micelles, increasing the surface area for lipase enzymes to act upon.
This process is crucial for fat digestion and absorption.
Step 3: Clarify misconceptions.
They do not digest fats directly or act on proteins or carbohydrates — they only assist by emulsification.
Step 4: Conclusion.
Hence, bile salts play a vital role in fat digestion by emulsification.