Describe how reduced NADP and ATP is produced during the light-dependent stage of photosynthesis.

ATP is produced during both cyclic and non-cyclic photophosphorylation.During cyclic photophosphorylation, a photon of a wavelength 700nm hits a chlorophyll molecule in PS1 and excites a single electron. As it leaves the molecule, the electron is taken up by an electron acceptor and passed along the electron transport chain to produce ATP. The electron returns to PS1 and can be re-excited.
Non-cyclic photophosphorylation involves both PS1 and PS2. An electron in PS2 is excited by the transfer of energy from photon of wavelength 680nm and travels down the electron transport chain, driving the synthesis of one ATP molecule. This electron replaces a lost electron in PS1. Once again, in PS1 an electron is excited however it is taken up by an electron acceptor NADP. To replace the lost electrons in PS2, photolysis occurs, producing H+ and OH- and electrons. The H+ and the excited electron from PS2 are taken up by NADP to form reduced NADP.