Fig. 4.
Comparison of PBD signals on the four S-transitions measured for PSII membranes in H2O (black) and D2O (red) at 20 °C. Thin lines, experimental data; thick lines, simulations with single-exponential functions plus offset, except for the S0 → S1 transition, for which a double-exponential function plus offset was used (Fig. S7 and Table S2). The respective rate constant ratio is indicated (KIE = kH2O/kD2O). The PBD amplitudes differ because of different thermoelastic properties of H2O and D2O.