Cycloartenol is a sterol precursor in photosynthetic organisms and plants. The biosynthesis of cycloartenol starts from the triterpenoidsqualene. Its structure is also related to triterpenoidlanosterol. Sterols, or steroid alcohols are a subgroup of steroids with a hydroxyl group in the 3-position of the A-ring. ... The leaf is the primary site of photosynthesis in plants. ... Biosynthesis is a phenomenon where chemical compounds are produced from simpler reagents. ... Terpenes are a class of hydrocarbons, produced by many plants, particularly conifers. ... Squalene is a natural organic compound originally obtained for commercial purposes primarily from shark liver oil, though there are botanical sources as well, including rice bran, wheat germ, and olives. ... Terpenes are a class of hydrocarbons, produced by many plants, particularly conifers. ... Lanosterol is a tetracyclic triterpenoid which is the compound from which all steroids are derived. ...