A key concept in biological sciences including pharmacology and toxicology is that bioactive small molecules such as drugs, hormones, and nutrients must achieve adequate concentration at a target site in order to elicit a biological response. For many chemicals, the ultimate site of action is a cognate protein or 'receptor.' The main criteria for the operational term 'receptor' are the functions of recognition and transduction. By this definition, a receptor must recognize a distinct chemical entity and translate information from that entity into a form that the cell can interpret, and alter its state accordingly. This altered state may be a change in permeability, activation of a guanine nucleotide regulatory protein, or an alteration in the transcription of DNA. To differentiate a receptor from an enzyme, the recognition unit should not chemically alter the small molecule and, to differentiate from a binding protein, a receptor must produce a biochemical change and transmit the signal. Often the receptor is a protein and a single component of a large complex of macromolecules that may include other proteins, RNA, and DNA.
|Original language||English (US)|
|Title of host publication||Comprehensive Toxicology|
|Subtitle of host publication||Second Edition|
|Number of pages||24|
|State||Published - Jan 1 2010|
All Science Journal Classification (ASJC) codes