Oligomer vs. Polymer

Main Difference

The main difference between Oligomer and Polymer is that the substance composed of oligomer molecules and Polymer is a chemical compound with repeating structural units.

• Oligomer

  An oligomer ( (listen)) (oligo-, “a few” + -mer, “parts”) is a molecular complex of chemicals that consists of a few monomer units, in contrast to a polymer, where the number of monomers is, in principle, infinite. Dimers, trimers, and tetramers are, for instance, oligomers composed of two, three, and four monomers, respectively.

  In biochemistry, an oligomer usually refers to a macromolecular complex formed by non-covalent bonding of a few macromolecules like proteins or nucleic acids. In this sense, a homo-oligomer would be formed by few identical molecules and by contrast, a hetero-oligomer would be made of more than one, different, macromolecules. Collagen is an example of a homo-oligomeric protein that is composed of three identical protein chains. The term multimer () (multi-, “more than one” + -mer, “part”) is used with a meaning similar to that of oligomer in the context of proteins (although technical restrictions of word sense may exist).Many oils are oligomeric, such as liquid paraffin. Plasticizers are oligomeric esters widely used to soften thermoplastics such as PVC. They may be made from monomers by linking them together, or by separation from the higher fractions of crude oil. Polybutene is an oligomeric oil used to make putty. Greek prefixes are often used to designate the number of monomer units in the oligomer, for example a tetramer being composed of four units and a hexamer of six.

  In biochemistry, the term oligonucleotide – or, informally, “oligo” – is used for short, single-stranded nucleic acid fragments, such as DNA or RNA, or similar fragments of analogs of nucleic acids such as peptide nucleic acid or Morpholinos. Such oligos are used in hybridization experiments (bound to glass slides or nylon membranes), as probes for in situ hybridization or in antisense experiments such as gene knockdowns. It can also refer to a protein complex made of two or more subunits. In this case, a complex made of several different protein subunits is called a hetero-oligomer or heteromer. When only one type of protein subunit is used in the complex, it is called a homo-oligomer or homomer.

  Oligomerization is a chemical process that converts monomers to macromolecular complexes through a finite degree of polymerization. The actual figure for degree of polymerization is a matter of debate, often a value between 10 and 100.Telomerization is the process where an oligomer forms a telomer as a result of chain transfer. A telomere is a region of highly repetitive DNA at the end of a linear chromosome.

• Polymer

  A polymer (; Greek poly-, “many” + -mer, “part”) is a large molecule, or macromolecule, composed of many repeated subunits. Due to their broad range of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass relative to small molecule compounds produces unique physical properties, including toughness, viscoelasticity, and a tendency to form glasses and semicrystalline structures rather than crystals.

  The term “polymer” derives from the Greek word πολύς (polus, meaning “many, much”) and μέρος (meros, meaning “part”), and refers to a molecule whose structure is composed of multiple repeating units, from which originates a characteristic of high relative molecular mass and attendant properties. The units composing polymers derive, actually or conceptually, from molecules of low relative molecular mass. The term was coined in 1833 by Jöns Jacob Berzelius, though with a definition distinct from the modern IUPAC definition. The modern concept of polymers as covalently bonded macromolecular structures was proposed in 1920 by Hermann Staudinger, who spent the next decade finding experimental evidence for this hypothesis.Polymers are studied in the fields of biophysics and macromolecular science, and polymer science (which includes polymer chemistry and polymer physics). Historically, products arising from the linkage of repeating units by covalent chemical bonds have been the primary focus of polymer science; emerging important areas of the science now focus on non-covalent links. Polyisoprene of latex rubber is an example of a natural/biological polymer, and the polystyrene of styrofoam is an example of a synthetic polymer. In biological contexts, essentially all biological macromolecules—i.e., proteins (polyamides), nucleic acids (polynucleotides), and polysaccharides—are purely polymeric, or are composed in large part of polymeric components—e.g., isoprenylated/lipid-modified glycoproteins, where small lipidic molecules and oligosaccharide modifications occur on the polyamide backbone of the protein.The simplest theoretical models for polymers are ideal chains.

• Oligomer (noun)

  a polymer whose molecules consist of relatively few repeating units.