View source for Agonist

An agonist is a ligand ([[Molecule|molecules]] that bind other molecules) that can be a drug or an endogenous molecule that bind to a receptor and elicit a cellular response, usually a signalling pathway. An example of an endogenous molecule that would be an agonist could be a [[Neurotransmitter|neurotransmitter]] or a [[Hormone|hormone]], such as [[Estradiol|estradiol]] <ref>Berg et al., (2006) Biochemistry, 6th edition, New York, Pg 910</ref>&nbsp;. 

Another example of an agonist is [[Nicotine|nicotine]]. Nicotine is a natural compound and is the chemical that is found in tobacco. Nicotine acts as an [[Antagonist|antagonist]] by binding to the same receptor as the main excitatory neurotransmitter [[Acetylcholine|acetylcholine]] and mimics the action of this neurotransmitter, therefore eliciting a cellular response <ref>Silverthorn et al., (2009) Human Physiology: An Integrated Approach, 5th Edition, San Francisco, Pg 41</ref>. 

Partial agonist is a compound that binds to a receptor producing an incomplete response, therefore it is&nbsp;considered to be less potent. 

=== References  ===

<references /><br><references />