 Some anaerobic organisms use NADP+-linked hydrogenase, ripping a hydride from hydrogen gas to produce a proton and NADPH.NADPH provides the reducing equivalents for biosynthetic reactions and the oxidation-reduction involved in protecting against the toxicity of reactive oxygen species (ROS), allowing the regeneration of glutathione (GSH).NADPH is also used for anabolic pathways, such as cholesterol synthesis and fatty acid chain elongation.