281 



I 



H. E. Davenport 



TABLE 2 



The Effect of Treating Intact Pea Chloroplasts with Phenyl Mercury 

 Acetate on Their Capacity to Photoreduce NADP and Metmyoglobin 



Chloroplast Treatment 



Untreated 

 Treated with PMA 

 Inhibition (%) 



Rate of Reduction 

 ()Limoles/mg chlorophyll/h) 

 Metmyoglobin NADP 



168 



170 







60 

 20 

 66 



Reaction mixtures as Table 1 except that chloroplasts contained 0- 045 mg 

 chlorophyll. 



Photochemical 



+ 

 Reduction of NADP 



Additions 



04 _ 



Illumination 



time 



(mln^ 



Complete 



Ferredoxin 

 ADP etc . 



Ferredoxin 

 Flavoprotcin 



Ferredoxin 



I 



( 



Fig. 3. Effect of ferredoxin, chloroplast flavoprotein and a phos- 

 phate accepting system on IMADP reduction by protein-depleted 

 pea chloroplast fragments. 



Reaction mixtures contained (in 3 ml) four times extracted pea 

 chloroplast fragments equivalent to 0.015 mg chlorophyll and 

 (inMmoles) Tris HCl pH 8, 150; NADP, 0.5; NaCl, 20. Where 

 indicated ferredoxin, 0. 15 mg, flavoprotein 2.0 mg, and (in 

 /imoles) ADP, 0.5; Na2HP04, 5.0; MgCl2, 10 were added. 

 30, 000 lux, 20O air. 



