Monomer

In chemistry, a monomer (from Greek mono "one" and meros "part") is any of several small molecular structures that may be chemically bonded together to form long multi-part polymer molecules.

Examples of monomers are hydrocarbons such as the alkane, alkene, and alene (homologous) series. Other hydrocarbon monomers such as styrene and ethene form polymers to make plastics like polystyrene and polyethene.

Amino acids are natural monomers, and polymerize to form proteins.