Metabolism
Metabolism stands for the uptake, transport and chemical transformation of substances in an organism as well as the release of metabolic waste products into the environment. If the first case involves foreign substances, this is also referred to as foreign substance metabolism.
These biochemical processes (e.g. internal and external breathing, transport processes, nutrition ...) serve to build up and maintain the body substance (building metabolism), energy production (energy metabolism) and thus the maintenance of bodily functions. Essential for the metabolism are enzymes, which catalyse chemical reactions.