isoprene

(noun)

An unsaturated hydrocarbon, C5H8, that is readily polymerized; natural rubber (caoutchouc) is cis-1,4-polyisoprene, and trans-1,4-polyisoprene is present in gutta-percha and balata; it is the structural basis for the terpenes.

Related Terms

Examples of isoprene in the following topics:

  • Lipid Biosynthesis

    • Biological lipids originate entirely or in part from two distinct types of biochemical subunits or "building-blocks": ketoacyl and isoprene groups.
    • Using this approach, lipids may be divided into eight categories: fatty acids, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, and polyketides (derived from condensation of ketoacyl subunits); and sterol lipids and prenol lipids (derived from condensation of isoprene subunits ).
    • Terpenes and isoprenoids, including the carotenoids, are made by the assembly and modification of isoprene units donated from the reactive precursors isopentenyl pyrophosphate and dimethylallyl pyrophosphate.
    • One important reaction that uses these activated isoprene donors is steroid biosynthesis.
    • Here, the isoprene units are joined together to make squalene and then folded up and formed into a set of rings to make lanosterol.

  • Vitamins and Amino Acids

    • For example, menaquinone-4 (abbreviated MK-4), has four isoprene residues in its side chain.

  • Carotenoids and Phycobilins

    • All carotenoids are tetraterpenoids, meaning that they are produced from 8 isoprene molecules and contain 40 carbon atoms.