A monomer ( ) (, "one" + , "part") is a molecule that may bind chemically or supramolecularly to other molecules to form a (supramolecular) polymer. The process by which monomers combine end to end to form a polymer is called polymerization. Molecules made of a small number of monomer units (up to a few dozen) are called oligomers. The term "monomeric protein" may also be used to describe one of the proteins making up a multiprotein complex.