212 



Daniel I. Arnon 



150 



I 



Fig. 8. Microphotograph of 

 crystalline ferredoxin from 

 Nostoc (60) . 



TPN absent 

 gos phose : Ng 



708 m/t only 



708 -I- 663 



66 3-*' 708-^-663 



12 



Fig. 10. Effect of additional 

 illumination at 663 ni|i on 

 ferredoxin-dependent cyclic 

 photophosphorylation at 7O8 n>n 

 under anaerobic conditions (13). 



Eo,PH7 



TPN 



LIGHT 



OH-(IO"^M) 



Fig. 9. Scheme for two photoreactions and their relation to 

 cyclic and noncyclic photophosphorylation in chloroplasts (13) • 



