Lipids are heterogeneous group of water insoluble compounds which are oily or greasy in consistency but soluble in non-polar solvents like ether, chloroform, benzene etc. For examples, fatty acids, fats, oils, waxes, certain vitamins and hormones are considered as lipids. Lipids are composed of C, H, O, like carbohydrates but poor in oxygen and therefore require more oxygen for oxidation [...]
Much more is known about the specific lipid composition of cell membranes, because the lipids are more readily extracted from the membranes using a variety of organic solvents. Once extracted from isolated membranes, the lipids may be separated and identified using chromatographic or other procedures. Nearly all the membranes studied so far appear to contain the same types of lipid [...]
The nonsaponifiable lipids (also known as simple lip- ids) are lipids that do not contain fatty acids as constituents. Two major classes of nonsaponifiable lipids are the terpenes and the steroids. 1. Terpenes: The terpenes include certain fat-soluble vitamins (such as vitamins A, E, and K), carotenoids (pigments of plant cells that are involved in photosynthesis), and certain coenzymes (such [...]