Receptor (biochemistry)
For other uses, see Receptor (disambiguation). An example of membrane receptors . Ligands, located outside the cell Ligands connect to specific receptor proteins based on the shape of the active site of the protein. The receptor releases a messenger once the ligand has connected to the receptor. In biochemistry and pharmacology, a receptor is a protein molecule that receives chemical signals from outside a cell. [1] When such chemical signals bind to a receptor, they cause some form of cellular/tissue response, e.g. a change in the electrical activity of a cell. There are three main ways the action of the receptor can be classified: relay of signal, amplification, or integration. [2] Relaying sends the signal onward, amplification increases the effect of a single ligand, and integration allows the signal to be incorporated into another biochemical pathway. [2] In this sense, a receptor is a protein-molecule that recognizes and responds to endogenous chemical signals,