ABSTRACT
The term ‘prenyllipids’ designates a vast family of compounds originating from isopentenyl diphosphate, the so-called biogenetically active isoprene unit, which shares its hydrophobic properties with the more common acyl lipids. Most carotenoids derive from the head to head condensation of two geranyl-geranyl diphosphate (GGDP) units. The complexity of the biosynthesis of terpenoids is illustrated by the cyclases, which will convert in one or two steps geranyl diphosphate, farnesyl diphosphate and GGDP into the huge array of different carbon skeletons characteristic of the terpenoid family of natural products. Plastoquinone plays a central role in oxygenic photosynthesis; it provides the electronic connection between the two photosystems and generates a transmembrane electrochemical proton gradient used for energy transduction and subsequent synthesis of adenosine triphosphate. Sterols are generally localised in the cytoplasm, where they are associated with the endomembrane continuum and are concentrated especially in the plasma membrane.
