210 



Daniel I. Arnon 



Hydrogenose from 

 Desu^fovibrb 



Fig. 1. Effect of extracting 

 and restoring plastoquinone to 

 spinach chlorop lasts on photo- 

 production of TPN with either 

 water (OH') or ascorbate as 

 electron donor (l8). 



30 40 50 

 minutes 



Fig. 2. Photoproduction of 

 hydrogen gas by spinach chlor- 

 oplasts supplemented by a 

 hydrogenase from Desulf qvibrio 

 desulfuricans. H2 was identi- 

 fied by adsorption on palla- 

 dium asbestos (Pd-asb) (22,25> 



"T I r 



' 1 ' 1 T- 



Hydrogenic photophosphorylotion 



20 30 



minutes 



Fig. 3* Photoproduction of 

 hydrogen coupled with photo- 

 phosphorylation by spinach 

 chloroplasts supplemented 

 with a hydrogenase from 

 Desulfovibrio desulfuricans 



hydrogenase 



flovoprotein 



Fig. 5. Diagrammatic repre- 

 sentation of the role of 

 ferredoxin as an electron 

 carrier (9) . 



(26,27) 



