340 



LIGHT AND LllE 



TRANSPARENT 

 CONDUCTORS 



t t 



PH THALOCYANINE ORTHO-CHLORANIL 



^ 



VIBRATING REED 

 ELECTROMETER 



Fig. 19. Schematic diagram of polaii/ation apparatus. 



additional accumulation of positive charge in the phthalocyanine. 

 This is exactly what happened (40) , and it is a photochemically in- 

 duced separation of oxidizing power (positive holes) and reducing 

 power (quinone double-negative ions) . Presumably, this sort of 

 thing could occur in the individual layers which can actually be seen 

 in the chloroplasts. 



The Relation to the Photosynthetic Apparatus 

 What bearing does this information have on the photosynthetic 

 apparatus itself? The obvious relationship is that the phthalocyanine 

 might be considered as a model for the chlorophyll layer itself. The 

 electron acceptor, here listed as o-chloranil, might indeed be some 

 electron acceptor in the chloroplasts such as Coenzyme Q255 (Plasto- 

 quinone) (8, 20, 41, 48, 60), which conceivably could have a func- 

 tion similar to the function that the o-chloranil has in the model 

 system, but witli certain tlifferences. 



Electron Spin Resonance i)i Chloroplast Materials 



If this is a model for the actual chloroplast behavior, then we 

 should see some of these electronic properties in the chloroplast it- 

 self. First of all, the change of absorption s])ectrum in the chloro- 

 plasts from that of a true solution has been mentioned earlier. Un- 

 fortunately, we cannot place electrodes on either side of the lamellar 

 layers of the chloroplasts as we have been able to do in the phthalo- 

 cyanine system, but there arc a number of properties which can be 



