Fat Digestion: Emulsification, Lipolysis, Micelle Formation, Absorption, and Chylomicron Transport

Steps of Fat Digestion and Absorption

1. Emulsification: Lingual lipase in mouth begins fat breakdown. In stomach, churning and acid continue. In small intestine, bile salts from liver break fats into smaller droplets (emulsion).

2. Lipolysis: Pancreatic lipases hydrolyze emulsified fats into fatty acids and glycerol.

3. Micelle Formation: Fatty acids and glycerol form micelles—water-soluble exterior, fat-soluble interior—to traverse the aqueous intestinal environment.

4. Absorption: Micelles deliver fatty acids and glycerol to intestinal cells (enterocytes). Fatty acids absorbed into enterocytes; glycerol absorbed separately.

5. Chylomicron Formation: In enterocytes, fatty acids are re-esterified and packaged with proteins into chylomicrons (triglyceride transporters).

6. Transport: Chylomicrons enter lymphatic system, then bloodstream, delivering triglycerides to tissues for energy or storage.

This process ensures dietary fats are broken down, absorbed, and utilized or stored.