Oligomer

An oligomer (from Greek ὀλίγοι oligoi, Few ' and μέρος meros, part ') is a molecule that is composed of several structurally identical or similar units. With a larger number of units is referred to as a polymer. The distinguishing criterion according to IUPAC is whether a small change in the number of units already causes a significant change in the properties.

A single unit is called a monomer. An oligomer having two, three, four ... units is a dimer, trimer, tetramer, etc. (see Greek numerals ).

Are all subunits are identical, one speaks of a homomer, at different by a heteromer.

Oligomeric occur, inter alia, in the course of the polymerization (see, for example, urea resin ) or vice versa in the cleavage of polymers ( see, e.g., enzyme digestion ).

Language use in biochemistry

Typically, the units of an oligomer are covalently linked. Exceptions can be found in biochemistry. There is meant by a " oligomeric protein " is not about one of only a few amino acid units, that would be an oligopeptide, but a protein complex, see quaternary structure. Thus, a hemoglobin ( heteromeric ) tetramer. A collagen fiber one ( homomeric ) trimer.