CHAIN to PS I, EXCITATION of electrons, transfer to another acceptor, and finally downhill to NADP+ REDUCING it to NADPH + H+ is called the Z scheme, due to its characteristic shape.Explanation-The splitting of water in the presence of sunlight is called photolysis.It occurs during non-cyclic photophosphorylation.It results in the supply of electrons to PSII and the protons to NADP+.O2 is liberated during this process. Electrons released from water finally reach NADP+ through PSII and PSI. Thus NADP+ is reduced to NADPH + H+. The NADP reductase enzyme is located on the stromal side of the membrane. Along with electrons that come from the acceptor of electrons of PS I, protons are necessary for the reduction of NADP+ to NADPH+ H+. These protons are also removed from the stroma.