Photophosphorylation ADP + Pi -- Light [right arrow] ADP
The energy captured by ADP and Pi to form ATP through photophosphorylation. At that point, another photon causes a similar excitation of the P700 reaction center as PSI, and again the excitation energy is transferred to electrons and transports them through a similar electron transport scheme.
It is possible for PSI to work independently of PSII, causing electrons to be raised to a high energy state, received by the other acceptor, and then passed downhill by the electron transport scheme, forming ATP along the way through cyclic photophosphorylation, as shown in Figure 10-4.
Jagendorf, "Uncoupling photophosphorylation
by detergents," Biophysics Including Photosynthesis, vol.
: Formation of ATP utilizing light energy in photosynthesis.
Above 40 [degrees] C, PSII was inhibited and photophosphorylation ceased (Stidham et al., 1982).
Sites of heat sensitivity in chloroplasts and differential inactivation of cyclic and noncyclic photophosphorylation by heating.
Contribution from electron transport and photophosphorylation. Plant Physiol.
PMA inhibits both Hill activity and photophosphorylation
(Siegenlthaler & Packer, 1965), as well as the dark reduction of cytochrome [C.sub.554] in whole cells of Chlamydomonas reinhardi, and inhibits either ferredoxin or ferredoxin-NADP oxidoreductase (Hiyama et al., 1970).