Biochemistry 4th Edition by Reginald Garrett, Charles Grisham

Exercise 16

The energetics of hydroquinone reduction by photosynthetic reaction centers The reduction of membrane-associated quinones, such as coenzyme Q and plastoquinones, is a common feature of photosystems (see Figures 21.15, 21.20, and 21.22). Assume Eo' for PQ/PQH₂ = 0.07 V and the potential of the ground-state chlorophyll molecule = 0.5 V, calculate G for the reduction of plastoquinone by
a. 870-nm light.
b. 700-nm light.
c. 680-nm light.