When a molecule of one glycerol molecule and three fatty acid molecules (R-COOH) join together, a condensation reaction takes place (ester bond formation) where three water molecules are removed and a basic lipid is formed which is called triglyceride. The basic structure of a lipid comprises of a glycerol and three fatty acids shown in Figure 1. They mostly include fats, oils, waxes, hormones and certain components of cell membrane. Lipids are the diverse group of compound that are made up of fatty acids and their derivates. They are mostly soluble in solvents such as alcohol, ethers and chloroform but insoluble in water. They are hydrophobic (water-fearing) in nature. Lipids are the class of organic compounds which means they are carbon containing compounds. In aqueous solution phospholipid molecules are the main component of the cell membrane in animal and plant cells and form a lipid bilayer of cell surface membranes.Phospholipids are polar molecules where they have a hydrophilic phosphate ‘head’ and a hydrophobic ‘tail’ of two fatty acids making them.A phospholipoid structure is where one fatty acid group of a triglyceride is substituted with a phosphate containing group.A fatty acid that has more than one double bond (=) is called a polyunsaturated fatty acid and if one double bond is present they are termed monounsaturated fatty acid.Hydrolysis, addition of a water molecule, of a triglyceride form fatty acids and glycerol.A condensation reaction (removal of water) between a glycerol molecule and fatty acid forms an ester bond.Triglycerides and phospholipids are two groups of lipids.One molecule of glycerol and three molecules of fatty acid come together via a condensation reaction to form a triglyceride.Lipids are associated with certain disorders such as atherosclerosis and obesity.They are the building blocks of many higher molecular weights compounds.They are the big source of energy within the body.Lipids are a heterogeneous group of compounds that are soluble in solvents like alcohol and benzene but insoluble in water.

What is the importance of phospholipids?.

Where does the synthesis of lipids take place?.

Structure of lipids download