Metabolism is the set of life-sustaining chemical reactions in organisms. The three main purposes of metabolism are: the conversion of food to energy to run cellular processes; the conversion of food/fuel to building blocks for proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of nitrogenous wastes. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments. (The word metabolism can also refer to the sum of all chemical reactions that occur in living organisms, including digestion and the transport of substances into and between different cells, in which case the above described set of reactions within the cells is called intermediary metabolism or intermediate metabolism).
Metabolic reactions may be categorised as catabolic – the breaking down of compounds (for example, the breaking down of glucose to pyruvate by cellular respiration); or anabolic – the building up (synthesis) of compounds (such as proteins, carbohydrates, lipids, and nucleic acids). Usually, catabolism releases energy, and anabolism consumes energy.
The chemical reactions of metabolism are organised into metabolic pathways, in which one chemical is transformed through a series of steps into another chemical, each step being facilitated by a specific enzyme. Enzymes are crucial to metabolism because they allow organisms to drive desirable reactions that require energy that will not occur by themselves, by coupling them to spontaneous reactions that release energy. Enzymes act as catalysts – they allow a reaction to proceed more rapidly – and they also allow the regulation of the rate of a metabolic reaction, for example in response to changes in the cell's environment or to signals from other cells.
This function of the body to create and use the energy for itself, has been illustrated in the vedas in detail, the corollary used in the vedas and the connotations as used in the modern science is veritably different, but both have “behoved” in their illustration about metabolism.
Metabolism, which is mentioned in the vedas as the throat chakra/cortex manifestation, which has the possibility of swinging two ways jaagrit ( activated) and Supt (dormant) (hyper and hypo, as referred in modern medicine), but either of the displacement from the optimum level is bad for the body. The use of the breath to regulate this cortex, is one of the measure which can be adopted to regulate “metabolism”, but having said that, it is advisable to undertake throat chakra meditation/yoga for maintaining it at healthy limits.