In the fields of pharmacology and biochemistry, a small molecule is a low molecular weight organic compound which is by definition not a polymer. The term small molecule, especially within the field of pharmacology, is usually restricted to a molecule that also binds with high affinity to a biopolymer such as protein, nucleic acid, or polysaccharide and in addition alters the activity or function of the biopolymer. The upper molecular weight limi...
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In the fields of pharmacology and biochemistry, a small molecule is a low molecular weight organic compound which is by definition not a polymer. The term small molecule, especially within the field of pharmacology, is usually restricted to a molecule that also binds with high affinity to a biopolymer such as protein, nucleic acid, or polysaccharide and in addition alters the activity or function of the biopolymer. The upper molecular weight limit for a small molecule is approximately 800 Daltons which allows for the possibility rapid diffuse across cell membranes so that they can reach intracellular sites of action. In addition, this molecular weight cutoff is necessary but insufficient condition for oral bioavailability.
Small molecules can have a variety of biological functions, serving as cell signalling molecules, as tools in molecular biology, as drugs in medicine, and in countless other roles. These compounds can be natural (such as secondary metabolites) or artificial (such as...
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