What is the function of bile salts in digestion?

• A. They bind calcium to prevent precipitation
• B. They activate pancreatic enzymes
• C. They form micelles with hydrophilic portions facing outward and hydrophobic portions inward to accommodate lipids
• D. They hydrolyze triglycerides

Answer: (C)

Bile salts act as detergents in the intestine to emulsify fats and form micelles that solubilize lipid digestion products for absorption. Their amphipathic nature means they have hydrophobic faces that trap lipids inside and hydrophilic faces that face the watery lumen, placing the lipid core inside a surface that can be carried through the aqueous environment to the intestinal wall. This arrangement increases the surface area for lipase to work and delivers fatty acids and monoglycerides to the brush border for uptake. They don’t activate pancreatic enzymes, hydrolyze triglycerides themselves, or bind calcium to prevent precipitation, which are handled by other processes or molecules.