li. L. STREHLER AXD D. D. HENDLEY 



603 



} B C DE 



1 M ii 





Fig. 1. Apparatus used in continuous measurement of ATP levels during photo- 

 synthetic phosphorylation. See text for detailed description. 

 Symbols: 

 A 6 v-18 amp ribbon filament lamp — burner at 8 v. 



Condensing lens 



Water-filled heat filter 



#25 Wratten filter 



#26 Wratten filter 



#29 Wratten filter 



#2408 Corning filter 



.Sample cuvette 



#9782 Corning filter 



#6.5 Wratten filter 



5819 Photomultiplier 

 .\I Signal lead 

 \ High voltage lead 

 O Aminco photometer, Model 1803-014 



Baird Atomic H.V. Supply, Model 312 



1-mv, one-second Brown recorder 



Lucite cuvette 



Polyethylene tubing spacer 



B 

 C 

 D 

 E 

 F 

 G 

 H 



.1 



K 



L 



P 



Q 

 R 



S 



the rapid decay of luminescence following the cessation of illumina- 

 tion and that the steady dark level gradually increases with successive 

 light periods. 



The time course of the rise in luminescence on initial illumination 

 is depicted in Fig. 3. Apparently the rate of ATP synthesis is quite 

 high after a few seconds of illumination despite the apparent absence 

 of ADP or ATP in the reaction mixture prior to illumination, as 



