Lipids are those organic compounds which are soluble in non-polar solvents (eg-acetone, ether, chloroform, benzene etc.) but insoluble in water. The most important role of lipids is to be its biofuel. Lipids provide more energy than carbohydrates.
Excess lipids are stored in the body and used when needed. They also provide protection to the internal organs. Since fats are poor conductors of heat, they provide good resistance.
Classification of Lipids
Based on the products of hydrolysis, lipids are of three types.
(i) Simple Lipids
They give fatty acids and alcohol on hydrolysis. Example fats, oils and waxes etc.
(ii) Compound Lipids
They on hydrolysis give fatty acids, alcohols and other compounds like phosphoric acid, sugar etc. Example phospholipids, glycolipids etc.
(iii) Derived Lipids
These lipids do not contain any ester chain. These are the hydrolysis products of simple or compound lipids that acquire the properties of lipids. There are two types of lipids based on the nature of fatty acids, alcohols (eg-sterols), vitamins D, E and K.
(i) वसा (Fats)
The lipids in which the fatty acid present is saturated are called fats and are solid at room temperature. They are usually synthesized in animals. Example butter etc.
The fatty acids present in them are unsaturated and are liquid at room temperature.