What is the effect of emulsification and micelle formation on lipid digestion?

• A. They block absorption of fats
• B. They enable triglycerides to be hydrolyzed by intestinal lipases and esterases
• C. They increase absorption of proteins
• D. They convert fatty acids to glucose

Answer: (B)

Emulsification and micelle formation enable lipids to be enzymatically digested and absorbed. Emulsification breaks large fat droplets into tiny droplets, increasing the surface area available for pancreatic lipase to act on triglycerides at the fat–water interface. This enzyme, aided by factors like colipase, hydrolyzes triglycerides into free fatty acids and monoacylglycerol (with esterases handling other lipid esters as needed). The resulting digestion products are poorly soluble in the watery intestinal environment, so bile salts form mixed micelles that solubilize fatty acids, monoacylglycerol, cholesterol, and fat-soluble vitamins, carrying them to the intestinal mucosa for uptake. Inside enterocytes, these products are reassembled into triglycerides and packaged into chylomicrons for transport. Therefore, emulsification and micelle formation are essential to make fat digestion possible and to enable efficient absorption.