Bio Chemistry

BIOCHEMISTRY 3(2+1)

Lesson 8 : Lipids- Introduction, Classification and Functions

Triacylglycerols or glycerolipids

1. Glycerolipids are composed mainly of mono-, di- and tri-substituted glycerols. It is the most well-known being the fatty acid esters of glycerol (triacylglycerols), also known as triglycerides.
2. Made of 3 fatty acyl residues are esterified to glycerol.
3. Very hydrophobic, neutral in charge ---> can be stored in anhydrous form.
4. Long chain, saturated triacylglycerols are solid at RT (fats).
5. Shorter chain, unsaturated triacylglycerols are liquid at RT (oils).
6. Lipids in our diet are usually ingested as triacylglycerols and broken down by lipases to release fatty acids from their glycerol backbones
7. Also occurs in the presence of detergents called bile salts.
8. Form micelles around fatty acids that allow them to be absorbed by intestinal epithelial cells.
9. Transported through the body as lipoproteins.
10. The hydrolysis of the ester bonds of triacylglycerols and the release of glycerol and fatty acids from adipose tissue is called fat mobilization