Light reaction occurs in grana of chloroplast in which light energy causes excitation of electrons which then passes through different carriers that results in generation of ATP. This process is known as Photophosphorylation. In non-cyclic Photophosphorylation electron excited from PSII is passed to pastoquinone via phaeophytin, then through cytochromes to PSI. PSI than passes the electrons to Ferrodoxin and then NADP is finally reduced.