The noncyclic photophosphorylation involves both the photosystems PS I and PS II. The electrons get excited up when the PS II absorbs 680 nm wave length of light. Then an electron acceptor accepts and passes it to electron transport system of cytochrome. Later these electrons are passed to PS I. Here also when the PS I absorbs 700nm wave length of light the electrons get excited and transfer to an acceptor molecule which is having greater redox potential. These electrons are then moved to an electron rich NADP+ so that it get reduced to NADPH +H+. This pathway of noncyclic transport of electrons taking place in the Z pattern is known as Z scheme.