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
2.1. Fatty acid
FATTY ACIDS
Fatty acids are building block of most lipids, made of long chain organic acids having one polar carboxyl group (head) and a non-polar hydrocarbon chain (tail).
These are aliphatic carboxylic acids containing long hydrocarbon chains ranging from C-4 to C-24.
Based on the bonds that exist within the hydrocarbon chains, fatty acids can be saturated or unsaturated.
• Saturated fatty acid is a long-chain carboxylic acid containing only C-C single bonds.
• Unsaturated fatty acid is a long-chain carboxylic acid containing one or more C-C double bonds
• Unsaturated fatty acids occur mostly in cis form e.g oleic acid rather than trans form e.g elaidic acid.