What occurs during the second step of lipid absorption?

During lipid absorption, the second step involves the diffusion of micelles into the cell membrane of intestinal epithelial cells. Micelles, which are formed in the intestinal lumen from bile salts, monoglycerides, and free fatty acids, aid in the solubilization of lipids. Once the micelles reach the intestinal epithelium, they interact with the brush border of the enterocytes.

The lipids within the micelles can then diffuse through the lipid bilayer of the cell membrane easily due to their hydrophobic characteristic. This process is crucial for the successful uptake of dietary lipids, including fats and fat-soluble vitamins, into the enterocytes where they can be processed further. The absorption of lipids is a complex event that requires both the formation of micelles and their interaction with the cell membrane to ensure efficient nutrient uptake.