Biochemistry is study of the chemical substances and processes that undergo during development and life. It deals with the chemistry of life, and as such it draws on the techniques of analytical, organic, and physical chemistry.

All chemical changes within the organism—either the degradation of substances, generally to gain necessary energy, or the buildup of complex molecules necessary for life processes are collectively called metabolism.Biochemistry enters into the investigation of chemical changes in disease, drug action, and other aspects of medicine, as well as in nutrition & genetics.