Fig. 7.
Simulations of the O-J-I(=P) ChlF rise (see text) and of the model forms of photosystem (PS) II in the excited state, which mainly contribute to the (chlorophyll a) fluorescence transient, are shown on a logarithmic time scale. Abbreviations: (L-P)*, the excited state of the PSII antenna, which is equilibrated among all light harvesting Chls, including P680; Ph, pheophytin; A and B, the first and second plastoquinone acceptors of PSII (QA and QB). The time course of the PSII model form (L-P)*PhAB at the beginning of the transient, which represents excited open PSII RCs (i.e. with oxidized QA), is at the origin of the minimal ChlF, FO. Modified from Lazár (2003).