A monomer is a molecule that forms the basic unit for polymers, which are the building blocks of proteins. Monomers bind to other monomers to form repeating chain molecules through a process known as polymerization. Monomers may be either natural or synthetic in origin.
Oligomers are polymers consisting of a small number (typically under 100) of monomer subunits. Monomeric proteins are protein molecules that combine to form multi-protein complexes. Biopolymers are polymers consisting of organic monomers found in living organisms.