514 



Leo P. Vernon, Waldo S. Zaugg and Elwood Shaw 



TABLE 2 



Rates of PMS Photoreactions with Spinach Chloroplasts 



The reaction conditions were those given for Figures 1 to 3 for the appro- 

 priate quinones. 



Per cent Per cent 



Quinone Triton X-100 Deoxycholate 



UQi 



UQ6 



TMQ 



0.4 



0.4 



0.33 



Rate of 



Photoreaction 



pmoles/hr/mg Chloroplasts 



Photooxidation Photoreduction 



49 

 160 

 600 







620 



240 



450 



790 



1740 



The stimulation of the PMS photoreactions by the presence of Triton 

 X-100 caused us to investigate the activity of isolated chlorophyll a. As 

 shown in Figure 4, chlorophyll a in the presence of Triton X-100 Eas the 



Fig. 4. Sensitization of PMS photo- 

 reactions by chlorophyll a in the 

 presence of detergents. "Chloro- 

 phyll a was added to the reaction 

 mixture from a methanol solution 

 to a final concentration of 4 pgrams. 

 Other conditions as in Figures 1-3. 



2 



MINUTES 



