This is an old revision of this page, as edited by Luxdormiens (talk | contribs) at 03:03, 17 November 2005. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Revision as of 03:03, 17 November 2005 by Luxdormiens (talk | contribs)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)
Chemistry
In chemistry, a dimer is a molecule composed of two similar subunits or monomers linked together. It is a special case of a polymer. Among the most common dimers are certain types of sugar; sucrose, for example, is a dimer of a glucose molecule and a fructose molecule.
A physical dimer is a term that designates the case where intermolecular interaction brings two identical molecules closer together than other molecules. There are no covalent bonds between the physical dimer molecules. Acetic acid is such a case where hydrogen bonds provide the interaction.
Biology
In biology, a dimer is a protein complex made up of two subunits. In a homodimer the two subunits are identical, and in a heterodimer they differ (though they are often still very similar in structure). The subunits do not need to be covalently linked, and usually aren't.