Primary metabolites: Plants produce thousands types of chemicals. Some of the organic compounds like carbohydrates, fats, proteins, nucleic adds, chlorophylls, hemes are required for their basic metabolic processes and found throughout the plant kingdom. These organic compounds are called primary metabolites.
(b) Secondary metabolites : These are derivatives of primary metabolites which are not involved in bast. They are produced in small quantities and their extraction from the plant is difficult, eg. carotenoids, anthocyanins, morphine, codeine, rubber etc.