The term metabolism is defined as the entire of spectrum of chemical reactions that occur in the living system. A metabolic pathway consists of a series of enzymatic reactions to produce desired products. The term metabolite is applied to a substrate or an intermediate or a product in metabolic reactions. Metabolism is broadly divide into two categories: catabolism and anabolism (Figure 8.1).

Figure 8.1 Outline of Catabolism and Anabolism