402 



LIGHT AND LIFE 



o 



o 



600 



650 



700 



700 



750 



600 650 



wdvelength m jj 



Fig. 3. Light-induced changes of absorption as observed in the long wavelength 

 region witii four types of aerobic plants. (Fast, reversible effects induced by 

 flashes of white light.) For the various spectra the shifts at 705 ni^u, are brought 

 to about equal height. Arrows indicate absorption maxima in the absorption 

 spectra plotted as broken curves. (From Kok, 14.) 



iii/j.. Together with the smaller negative change at 555 myu,, one could 

 interpret this as the oxidation of cytochrome / by the light (14) . (A 

 similar effect was found by Duysens (4) in red algae). We have shown 

 earlier (12) that this shift is a fast phenomenon induced by brief 

 flashes, like the negative 700 m^i, shift. 



