Classification of lipids

1. CLASSIFICATION OF LIPIDS
Dr. T.Sakthika
Assistant Professor
Department of Zoology
A.P.C.Mahalaxmi College for Women, Thoothukudi

2. Lipidsare water insoluble, oily, or greasy organic compounds soluble in non polar
organic solvents like alcohol, chloroform, acetone, benzene, etc. Lipids are composed of 3
fatty acids joined to an alcohol. Fatty acids are building blocks of lipids. The term Lipids
was first introduced by Bloor in 1943
Lipids are important component of diet
One gram lipid yields 9.3 kilocalories of heat. They are found in all organisms including
virus.
Properties of Lipids
Lipids may be either liquids or non-crystalline solids at room temperature.
Pure fats and oils are colorless, odorless, and tasteless.
They are energy-rich organic molecules
Insoluble in water
Soluble in organic solvents like alcohol, chloroform, acetone, benzene, etc.
No ionic charges
Solid triglycerols (Fats) have high proportions of saturated fatty acids.
Liquid triglycerols (Oils) have high proportions of unsaturated fatty acids.

4. 1. Simple lipids. They are esters of fattyacids with alcohols like glycerol (in neutral fats)
and cetyl alcohol (in water)
(a) Fats and oils which yield fatty acids and glycerol upon hydrolysis.
(b) Waxes, which yield fatty acids and long-chain alcohols upon hydrolysis.
2. Compound lipids are lipids liked with non lipids. They are also called heterolipids
(a) Phospholipids, which yield fatty acids, glycerol, amino alcohol sphingosine, phosphoric
acid and nitrogen-containing alcohol upon hydrolysis.
They may be glycerophospholipids or sphingophospholipid depending upon the alcohol
group present (glycerol or sphingosine).
(b) Glycolipids, which yield fatty acids, sphingosine or glycerol, and a carbohydrate upon
hydrolysis.
They may also be glyceroglycolipids or sphingoglycolipid depending upon the alcohol group
present (glycerol or sphingosine).
3. Derived lipids are Hydrolytic product of simple and compound lipids . They include fatty
acid, glycerol, sphingosine and steroid derivatives.
Steroid derivatives are phenanthrene structures that are quite different from lipids made up
of fatty acids.