Processing of Dietary Lipids
Most of the fat we eat is in the form of triacylglycerides.
- In the intestine, our food encounters the bile
. Intestinal enzymes attack the triacylglycerides and glycerophospholipids, resulting in the release of fatty acids. - The fatty acids are taken up by intestinal cells which puts them back into the form of triacylglycerides.
- Triacylglycerides are attached to lipoproteins and released first into the lymph and from there into the blood.
- In the blood these are attacked by the enzyme lipoprotein lipase which releases fatty acids.
- The fatty acids are immediately picked up by the protein albumin (remember, lipids are not very soluble in aqueous solutions) which carries them to tissues such as adipocytes.
- In the tissues the fatty acids are reassembled with glycerol to make triacylglycerides and stored there until needed.
We also consume some cholesterol and glycerophospholipids.
- The processing and transport of cholesterol is a somewhat different story with enormous health implications.
