Figure 8.

(A) Loss of absorption at 500 nm (ΔA₅₀₀) as a function of time. The rate of thermal decay, k was calculated from the initial slope. (B) Arrhenius plot for the thermal bleaching of rhodopsin determined at concentrations of 0 (black squares), 5 (gray squares), 10 (light gray squares), 20 (black triangles), 50 (gray triangles), and 100 (light gray triangles) mM OG. (C) Examples showing first-order nature of thermal bleaching. The ln of ΔA₅₀₀ is plotted against time under the following conditions: 0 mM OG, 344 K (circles); 20 mM OG, 336 K (diamonds); and 100 mM OG, 324 K (triangles). (D) The E_act as a function of OG concentration for rhodopsin thermal bleaching (black squares) are plotted. The E_act values determined from scan-rate dependence by DSC (gray squares) are shown for comparison.