Monomer


Monomer

A monomer (from Greek mono "one" and meros "part") is an atom or a small molecule that may bind chemically to other monomers to form a polymer[1]; the term "monomeric protein" may also be used to describe one of the proteins making up a multiprotein complex. The most common natural monomer is glucose, which is linked by glycosidic bonds into polymers such as cellulose and starch, and is over 76% of the mass of all plant matter.[2] Most often the term monomer refers to the organic molecules which form synthetic polymers, such as, for example, vinyl chloride, which is used to produce the polymer polyvinyl chloride (PVC).

Contents

Natural monomers

Amino acids are natural monomers that polymerize at ribosomes to form proteins. Nucleotides, monomers found in the cell nucleus, polymerize to form nucleic acids – DNA and RNA. Glucose monomers can polymerize to form starches, glycogen or cellulose; xylose monomers can polymerise to form xylan. In all these cases, a hydrogen atom and a hydroxyl (-OH) group are lost to form H2O, and an oxygen atom links each monomer unit. Due to the formation of water as one of the products, these reactions are known as dehydration or condensation reactions.

Isoprene is a natural monomer and polymerizes to form natural rubber, most often cis-1,4-polyisoprene, but also trans-1,4-polyisoprene..

Molecular weight

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 Greek prefix; e.g. a decamer is formed from 10 monomers. Larger numbers are often stated in English or numbers instead of Greek. Molecules made of a small number of monomer units, up to a few dozen, are called oligomers.

See also

  • List of publications in polymer chemistry
  • Prepolymer

Notes

  1. ^ Introduction to Polymers 1987 R.J. Young Chapman & Hall ISBN 0-412-22170-5
  2. ^ Cellulose. (2008). In Encyclopædia Britannica. Retrieved March 22, 2009, from Encyclopædia Britannica Online.
  3. ^ Campbell, Neil A.; Brad Williamson; Robin J. Heyden (2006). Biology: Exploring Life. Boston, Massachusetts: Pearson Prentice Hall. ISBN 0-13-250882-6. http://www.phschool.com/el_marketing.html. 

External links


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Look at other dictionaries:

  • monomer — MONOMÉR, monomeri, s.m. Substanţă chimică simplă, de obicei organică, cu greutate moleculară mică şi cu caracter instabil, care intră în constituţia unui polimer. – Din fr. monomère. Trimis de LauraGellner, 04.06.2004. Sursa: DEX 98  monomér s.… …   Dicționar Român

  • monomer — mon o*mer, n. (Chem.) The basic conceptual building unit of a polymer; a molecule of low molecular weight which may combine with other molecules to form a molecule in a chain or branched form having high molecular weight; as, amino acids are the… …   The Collaborative International Dictionary of English

  • monomer — monomer. См. мономер. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • monomer — (n.) 1914, from MONO (Cf. mono ) + Gk. meros part (see MERIT (Cf. merit) (n.)). Related: Monomerous …   Etymology dictionary

  • monomer — monòmēr m <G monoméra> DEFINICIJA kem. osnovna konstitucijska jedinica polimera …   Hrvatski jezični portal

  • monomer — ► NOUN Chemistry ▪ a molecule that can be linked to other identical molecules to form a polymer …   English terms dictionary

  • monomer — [män′ə mər] n. [ MONO + Gr meros, a part: see MERIT] a simple molecule that can form polymers by combining with identical or similar molecules monomeric [män′əmer′ik] adj …   English World dictionary

  • monomer — monomeric /mon euh mer ik/, adj. /mon euh meuhr/, n. Chem. a molecule of low molecular weight capable of reacting with identical or different molecules of low molecular weight to form a polymer. [1910 15; MONO + MER] * * * Molecule of any of a… …   Universalium

  • Monomer — Monomere (altgriechisch μόνος mono ein, einzel μέρος meros Teil, Anteil ) sind niedermolekulare, reaktionsfähige Moleküle, die sich zu molekularen Ketten oder Netzen, zu unverzweigten oder verzweigten Polymeren, zusammenschließen können. Im… …   Deutsch Wikipedia

  • monomer — mo|no|mer 〈Adj.; Chem.〉 aus einzelnen Molekülen bestehend; Ggs polymer [<grch. monos „allein“ + meros „Teil“] * * * mo|no|mer [↑ mono u. ↑ mer] nennt man ein Teilchen (Atom, Molekül) mit dem Einfachen der Molmasse (z. B. HgCl, NO2, H2C=CH2),… …   Universal-Lexikon


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