Define lipids
'lipids' defines substances as oils, fats and waxes which can be only characterized by a large array of properties. They are in general:
- coming from plant and animal origin;
- insoluble or immiscible with water but soluble in organic solvents such as chloroform, ether, benzene, acetone; and
- formed of long-chain hydrocarbon groups (carbon and hydrogen), but may also contain oxygen, phosphorous, nitrogen and sulphur.