Lipid comes from the Greek word meaning fat. Lipids may be defined as any one of the group of fats or fat-like substances characterized by their insolubility in water.
Like other organic compounds, all lipids re composed of a carbon skeleton with hydrogen and oxygen substitution.
Lipids may be classified as a mixed group of substances with the common characteristics of solubility in organic solvents. It can be classed as simple lipids, compound lipids and derived lipids.
Simple Lipids
Simple lipids are esters of fatty acids with alcohols with includes fats, oils and waxes
Fats are neutral esters of glycerol with saturated or unsaturated fatty acids. Triglycerides, esters of three fatty acids molecules with one glycerol molecule, account for more than 90% of the fat in animals.
Compound Lipids
Compound lipids are the esters of fatty acids and alcohols with nonlipid substances. According to the nature of nonlipid substances they are divided into 3 subclasses: phospholipid, glycolipids and lipoproteins.
Phospholipids (esters containing phosphoric acid in place of one mole of fatty acid)
Glycolipids (compounds of carbohydrate fatty acids and sphingosinol)
Lipoproteins (complexes of various lipids and proteins)
Derived Lipids
Derived lipids result from hydrolysis or enzymatic breakdown of simple and compound lipids.
This include fatty acids, alcohols, hydrocarbons, fat-soluble vitamins
Classification of lipid
