Redox Reactions in Monolayers

Upon illumination of a mixed monolayer of chlorophyll with ferridoxine in the presence of ascorbate, Brody and Owens [22] detected a shght change in the isotherm, which in their opinion is an indication of a reaction between these components. Upon illumination of mixed films of chlorophyll and oxidized cytochrome c, a reduction in the mean area per molecule by about 18% is observed. On the other hand, illumination of films of chlorophyll with reduced cytochrome increases the area per molecule significantly (by about 10%). The difficulty of interpreting very small effects lies in the fact that in the dark the area per molecule increases both for the films with reduced cytochrome c and for the mixture containing reduced cytochrome. At any rate, for the case with reduced cytochrome c, Brody and Owens believe that they observed an electron-transfer reaction stimulated by light  

Investigations of mixed monolayers of chlorophyll with plastocyanine revealed some slight reversible changes of the Volta potential. The magnitude of the effect depended on the illumination time and possibly points to the presence of an electron-exchange reaction between chlorophyll and plastocyanine  

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