Question

How do lipids affect the digestive system?

Answer 1

Lipids are considered fats. They are made into smaller pieces by bile that is made by the liver and stored in the gall bladder. They are then cut up by pancreatic lipase into 3 fatty acids + glycerol.

Explanation:

We have to know what a fat is: a fat is a non-polar molecule made up of 3 fatty acids (chains of Carbon and Hydrogen atoms (non-polar/insoluble) and a glycerol molecule (polar/soluble).

Note that fats are NOT soluble in water, since water is polar and it cannot dissolve non-polar molecules. They are in forms of droplets of fat on top of the water (same as the grease you see on a frying pan when you make eggs).

Since fats are insoluble, the bile (yellowing liquid) that is made in the liver and stored in the gallbladder will make the fat droplets smaller and separate them (does not cut them). This action is called emulsifying the fats.

The pancreas then makes an enzyme called pancreatic lipase which then follows up and cuts the fat into 3 fatty acid molecules and a glycerol. These are then absorbed in the small intestine and stored by your cells.

For more information, see this question on Socratic on how lipids are digested.