PHOSPHORYLATION OF R. ruhrum 



307 



/J M Pi 



hr X mg. Protei n 

 4.0 

 35 

 3.0 

 2.5 



2.0 

 1.5 

 1.0 



0.5 



/ 



/ 



100 



500 



600 



200 300 400 



Light Intensity {Foot Condles ) 



Fig. 2. Initial rates of light-induced phosphorylation as a function of light in- 

 tensity (against initial blanks). Crude cell-free preparations in 0.2 M glycylgly- 

 cine (potassium salt) containing 15 mg. dry weight protein per vessel with the 

 following additions: 10 /xM ADP, and 15 ^M orthophosphate. Final volume per 

 vessel 3.0 ml., pH of reaction mixture 7.5. Optical density of suspension 1.5 at 

 800 m^i. Temperature 25°C. Illumination. by incandescent lamps. 



ADP 



ATP 



Fig. 3. Schematic representation of phosphorylation linked to a photochemical 

 process (c/. ref. 9). (H) photochemically produced reductant; (OH) photochem- 

 ically produced oxidant; C, CH, oxidized and reduced intermediate carriers; 

 AH, exogenous electron donor ("sparking" agent) reduces C to CH in the dark; 

 [P] phosphorylating system. 



oxygen. It is not known at which point along this chain of electron 

 transport phosphorylation occurs, its location in Fig. 3 being quite hy- 

 pothetical. 



