In this study, the sample transmittance was always measured at 865 nm and this is denoted by a subscript on T in Eq. 5. When normalized, the amplitudes of C A and C B give the relative amounts of Q B -depleted and Q B -Captisol datasheet active RCs in the sample. The ratios in each term of Eq. 5 gives the extent that each RC sample component contributes to see more the overall steady state saturation level. Method 2 A second method of analysis uses a single effective lifetime for the redox state of the whole system, regardless of whether it is a single component system or a multiple component system. The effective

rate constant of electronic equilibration, \( \tau_el^ – 1 \), is $$ \tau_el^ – 1 = I + k^\prime_\textrec = I + \left[ \fracC_A k_A + \fracC_B k_B \right]^

– 1 , $$ (6)and the effective charge recombination rate, or rate constant for electron transfer back to the bacteriochlorophyll dimmer (donor), \( k^\prime_\textrec = \tau_d^ – 1 \), is given by the term in brackets. The overall bleaching kinetics then follows the relation: $$ T_865^{{}} (I,t) = C\frac\alpha \cdot I_\exp \alpha \cdot I_\exp + k^\prime_\textrec \left( 1 – \exp \left[ - t(\alpha \cdot I_\exp + \tau_d^ - 1 ) \right] \right) . $$ (7) The factor C in Eq. 7 relates the measured transmittance buy Doramapimod in arbitrary units to the dimensionless theoretical quantity. The effective charge recombination lifetime, \( \tau_d = (k^\prime_\textrec )^ – 1 \), can also be considered as an “average survival time” of the charge separated state(s) however with respect to the donor (Agmon and Hopfield

1983; Abgaryan et al. 1998) in cases where charge recombination becomes multiexponential. It has been shown previously (Abgaryan et al. 1998; Goushcha et al. 2000) that the recombination kinetics for a complex RC system can be described using such a single effective decay parameter. For the general case of a system with a fixed structure and a finite number of localized electron states, the value of this effective decay parameter depends only on structural organization and not upon the actinic light intensity, with changes in this effective decay parameter value attributed to structural changes within the RC system. Method 2 describes a mixture of Q B -active and Q B -depleted RCs as a single homogeneous donor-acceptor system with a single effective recombination rate and is not independent of the more rigorous Method 1.