hydrocarbon metabolism terpene metabolism UPa:UPA00423 GO:0042214 Metabolism of terpenes, a class of hydrocarbons produced by many plants, particularly conifers. Terpenes are major components of resin, and of turpentine produced from resin. The name 'terpene' comes from 'turpentine'. Terpenes are derived from isoprene C5H8 units and have the basic formula of multiples of it, i.e., (C5H8)n. The isoprene units can be arranged in a linear way or forming rings. One can consider isoprene as one of nature's preferred building blocks. Terpenes can be classified according to the number of isoprene units that they contain: * Monoterpenes, C10H16, 2 isoprene units * Sesquiterpenes, C15H24, 3 isoprene units * Diterpenes, C20H32, 4 isoprene units * Triterpenes, C30H48, 6 isoprene units * Tetraterpenes, C40H60, 8 isoprene units * Polyterpenes with a large number of isoprene units If terpenes are further modified, for instance by adding hydroxyl groups or moving or removing a methyl group, the resulting compounds are called terpenoids. (Some authors also call these compounds terpenes.) [wikipedia]. pathway