| [Edit]
In biology, second messengers are low-weight diffusible molecules that are used in signal transduction to relay signals within a cell. They are synthesized or released by specific enzymatic reactions, usually as a result of an external signal that was received by a transmembrane receptor and pre-processed by other membrane-associated proteins. There are three basic types of second messenger molecules:
These intracellular messengers have some properties in common:
They can be synthesized/released and broken down again in specific reactions by enzymes.
Some (like Ca2+) can be stored in special organelles and quickly released when needed.
Their production/release and destruction can be localized, enabling the cell to limit space and time of signal activity.
|
|
