606 



LIGHT AND LIFE 



8 



12 3 4 5 6 7 



TIME (Minutes) 

 Fig. 5. Effect of addition of TPN on photosynthetic phosphorylation 

 in mixtures of chloroplasts and fireHy enzyme. 

 Conditions as in Fig. 2 except that TPN (1 /^tmole) was added at the time in- 

 dicated by the arrow, in place of PMS. 



DECREASE IN ATP LEVEL OF CHLOROPLASTS BY ILLUMINATION 



z 



UJ 



UJ 



o 



z 



UJ 



o 

 (/) 



UJ 



> 



I- 

 < 



UJ 



12 3 4 



TIME (Minutes) 

 Fig. 6. Evidence that illumination causes a reversible decrease in the ATP 

 level of mixtures of chloroplasts and firefly enzyme. 

 The reaction mixture contained 0.2 ml fnefly en/\me; 03 mi thioroplast siis 

 |>ensi()n: ().."> ml of 0.1 M NaJlPO,; 0.2. ml I'M.S (."> X 10"' M .solution). IPX 0.1. 

 ml (1.0 X 10- M solution) 0.10.") ml .AMP; 0.0') ml myokinase solution; l.-l ml 

 suspension medium. The rea<tion medium had been illuminated for about 10 

 minutes prior to the begiiuiiug of the tracing. L, light on; 1), light oil. 



