Introduction to Chemistry of Lipids
Lipids comprises heterogeneous group of compounds which are insoluble in water but soluble in non-polar organic solvents such us benzene, chloroform, and ether, present in all living organisms.
The group includes fats, oils, waxes and related compounds.
General Functions of Lipids
i. They are efficient energy sources.
ii. Serve as thermal insulators.
iii. They are structural components of the cell membrane.
iv. Serve as precursors for hormones (steroid hormones).
v. They also dissolve the vitamins, which are fat-soluble and assist their digestion.
2. Classification base on composition
2.6. classification and function of lipoprotein
Cholesterol and other lipids are carried on plasma lipoproteins.
• Cholesterol and cholesteryl esters, like triacylgycerols and phospholipids are relatively insoluble in water, but must be transported within the body.
• Therefore, they are carried in the blood plasma as lipoproteins.
• Lipoproteins are spherical complexes with hydrophobic lipids in the core and hydrophilic amino side chains at the surface which interacts with the aqueous environment.
• Chylomicrons: are the largest lipoproteins and the least dense which contain a high proportion of triglyceride.
• The apolipoproteins of chylomicrons are apoB-48,
apoE, and apoC-II.