Small molecule

Small Molecule

A small molecule is a low molecular weight organic compound that may regulate a biological process, with a size on the order of 1 nm. Most drugs are small molecules.

Overview

Small molecules can have a variety of biological functions, serving as cellular signaling molecules, the building blocks of cells, the intermediates of metabolism, or drugs in medicine. They may be natural or synthetic; the latter are often used in research and therapeutic applications.

Characteristics

Small molecules typically have a low molecular weight, under 900 daltons, allowing them to easily diffuse across cell membranes. This makes them ideal for certain research and therapeutic applications. They can be used to create a phenotype in cells, to modulate protein functions, or to model diseases.

Applications

In medicine, small molecules are often used as drugs to modulate a biological process. They can be administered orally and can reach intracellular sites of action, influence protein function and modulate cell signaling pathways.

In research, small molecules can be used to probe the function of genes and proteins in a process known as chemical genetics.

See also

• Drug discovery
• Medicinal chemistry
• Pharmacology
• Biochemistry
• Chemical biology
• Chemical genetics