METABOLISM
The whole complex of various chemical reactions going on in a cell is called cell metabolism. These reactions provide both breaking up of complex compounds and their synthesis and interconversion. They are enzymatic, as usual.
A certain sequence of enzymatic conversions of a substance in a cell is called metabolic fate. Various types of molecules, which take part in these reactions are integrated by the common term "metabolites". As the result of metabolic processes a living cell produces (reproduces) and maintains itself, and the whole organism uses al types of accessible energy for its vital functioning. Metabolism is regulated by specific molecules, bioregulators, which are cofactors, vitamins, and hormones.
Metabolic reactions, which result in biosynthesis of complex compounds of more simple, are called anabolic, and their complex is called anabolism. These reactions, as a rule, proceed with energy usage. Enzymatic disintegration of complex compounds for more simple constitute the complex of processes of catabolism ( hydrolysis, oxidation). During these reaction the supply of free energy in the system decreases.
One-substrate enzymatic reaction proceeding by Michaelis-Menten mechanism is considered to be an elementary metabolic process.