Hydrolysis of fats is a digestive challenge because fat molecules are insoluble in water.

Bile salts from the gallbladder secreted into the duodenum coat tiny fat droplets and keep them from coalescing, a process called emulsification.

Because the droplets are small, a large surface area of fat is exposed to lipase.

The hydrolyzed fat molecules form micelles, which diffuse into lacteal vessels.