1558 



PHOTOCHEMISTRY OF CHLOROPHYLL 



CHAP. 35 



at 2000 psi sedimented slower than those obtained by ultrasonic waves; 

 fractional sedimentation showed that the photochemical efficiency de- 

 creased with decreasing particle size. No evidence was obtained in sedi- 



100 



80 



UJ 



3 



< 60 



- 40 



20 



\ Activity 

 \ 

 \ 



N 



Dispersed 



chlorophyl 



_i_ 



5000 



PSI 



10,000 

 FOR DISPERSION 



15,000 



20,000 



Fig. 35.14. Loss of activity (per unit chlorophyll amount) and efficiency of 

 dispersion (percentage of chlorojjhyll dispersed by valving) as functions of pres- 

 sure (after Milner, Lawrence and French 1950). 



2 4 6 8 



HOURS AT 12,000 x g. 



Fig. 35.15. Sedimentation of chloroplast dispersions obtained by supersonics and 

 by the valve method (after French and Milner 1951). 



