A monomer (from Greek mono "one" and meros "part") is either an atom or a small molecule that has the potential of chemically binding to other monomers of the same species to form a polymer.[1] The most common biochemical monomer is glucose, which is linked by glycosidic bonds into polymers such as cellulose and starch, and is over 76% of the weight of all plant matter.[2]
Contents |
Amino acids are natural monomers and polymerize to form proteins. Nucleotides, monomers found in the cell nucleus, polymerize to form nucleic acids - most famously, DNA and RNA. Glucose monomers can polymerize to form starches, amylopectins and glycogen polymers. In this case the polymerization reaction is known as a dehydration or condensation reaction (due to the formation of water (H2O) as one of the products) where a hydrogen atom and a hydroxyl (-OH) group are lost to form H2O and an oxygen molecule bonds between each monomer unit.
Isoprene is a natural monomer and polymerizes to form natural rubber, most often cis-1,4-polyisoprene, but also trans-1,4-polyisoprene.
The lower molecular weight compounds built from monomers are also referred to as dimers, trimers, tetramers, pentamers, octamers, 20-mers, etc. if they have 2, 3, 4, 5, 8, or 20 monomer units, respectively. [3] Any number of these monomer units may be indicated by the appropriate prefix, eg, decamer, being a 10-unit monomer chain or polymer. Larger numbers are often stated in English in lieu of Greek. Polymers with relatively low number of units are called oligomers.
|
|