Figure 5.

Fluorescence decay kinetics of DCMU-treated PSII CC of T. vulcanus under F_o, F₁, and F_m conditions. A, Fluorescence decays recorded at 278 K at 685 nm, excited at 632 nm. The slower decay under F_m conditions corresponds to the higher fluorescence yield. When the RCs are closed by a STSF, the decay (F₁) is only slightly slower compared to F_o. B, Distribution of fluorescence lifetime components by their relative amplitudes (the lifetimes, in ps, are indicated above the bars). Inset: average fluorescence lifetimes. C, Gibbs free energy differences (ΔG) between different compartments of kinetic models—with three radical pairs—found for PSII core complex in both charge-separated (F₁, left) and light-adapted charge-separated (F_m, right) state (all rates are given in ns⁻¹).