386 



Max H, Homme r sand 



60 80 

 TIME (min.) 



Fig, 5. Effect of CCCP on respiration and photo- 

 synthesis in Chlorella pyrenoidosa . Pardee buffers) 

 adjusted to provide a constant 17o CO2 tension was used 

 in the center well of the Warburg vessels. The light 

 intensity was 1500 ft. candles. The curves are: •, 

 control; o, 10"5m CCCP; A, 3x10-5m CCCP; a, 8x10-5m 

 CCCP. 



to obtain approximately the same photosynthetic rates in the 

 controls, the relative effectiveness of different colors of light 

 in overcoming the photosynthetic induction lag caused by CCCP 

 was compared. It was observed that under the experimental 

 conditions, red light at wavelengths longer than 660mp was the 

 most effective in overcoming the lag caused by CCCP. White light, 

 adjusted to an intensity that gave the same photosynthetic rate 

 in the controls, was much less effective than red light, and blue 

 light was still less effective than white light (fig. 6), 



i 



It is surprising, in view of the fact that CCCP is known to be 

 such an effective uncoupler of photosynthetic phosphorylation in 

 isolated chloroplasts of higher plants ("), that this compound 



