ABSTRACT
Metabolism consists of two general phases, catabolism and anabolism. Catabolism involves the breakdown of substances toward their end products, usually with the release of energy that either is used immediately in other biochemical reactions, is stored, or is dissipated as heat. Anabolism involves the building of substances from different or less complex precursors into products that are more complex. This usually consumes energy, and the stored products may be important as energy reserves, as in the case of fat stores in adipose tissue. the Metabolic reactions of cells are the manifestations of life itself, and the basis for other vital phenomena such as reproduction, growth, and sensitivity to the environment. Metabolic rate is usually determined by indirect calorimetry during which the rate of consumption of oxygen is measured and then converted into its energetic equivalent, expressed in joules. Carbohydrate metabolism is fundamentally different in ruminant animals and in nonruminant animals.
