290 



ALLEN, WHATLEY, ROSENBERG, CAPINDALE, ARNON 



TABLE 111. Effect of riiosphorylated Compoiuicls on riiotos^'nthetic Carbon 

 Dioxide Fixation by Broken Chloroplasts (10 ^nioles CO2 added)" 



Additions 



None 



3-Phosphoglyceric acid 



llibose-5-phosphate 



Glucose-1-pho.sphate 



GIucose-6-phosphate 



Fructose-6-phosphate 



Fructose diphosphate 



" 3 Atnioles of each phosphorylated compound was added to the reaction mix- 

 ture. Other experimental conditions as described in (4). 



fixation in the absence of added chloroplast extract (CE), but in- 

 creased photosynthetic CO2 fixation in the presence of CE. Heating 



f?w 



F^«,ATP,TPM 



P ,CZ 



P ,CE,ATP,TPN 



P„ CE,ATP,TPN 

 FDP 



Fig. 1. Diagrammatic representation of the effects of various addenda on CO2 

 fixation by broken chloroplasts. Experimental conditions as in (4). 



the CE ahnost completely abolished its effect on COo fixation by 

 broken chloroplasts. The effects of added pyridine nucleotides and 

 ATP, with and without CE, are shown in Table II. 



A further marked increase in CO2 fixation by the broken chloroplast 

 system was obtained on adding small quantities of any one of a number 



