A hormone is a chemical that acts as a messenger transmitting a signal from one cell to another.
When it binds to another cell which is the target of the message, the hormone can alter several
aspects of cell function, including cell growth, metabolism or other function Hormones can
be classi ed according to chemical composition, solubility properties, location of receptors,
and the nature of the signal. Hormones that bind to tie surfaces of cells communicate with
intracellular metabolic processes through intermediary molecules called second messengers
(the hormone itself is the rst messenger), which are generated as a consequence of the