612 LIGHT AND LIFE 



TABLE 3 

 Relation of Peroxide Production to Phosphorylation with FMN as Cofactor 



Phosphorylation and acetaldehyde formation given as ^moles per mg chlorophyll 

 per hour. 



figures in the last column show the ratio of phosphate esterified to 

 acetaldehyde formed. Note how this ratio changes from 0.6 to 1.2 

 as the oxygen tension is decreased, though the photophosphorylation 

 rate remains essentially constant. 



The results of an equivalent set of measurements with K3 are given 

 in Table 4. Here we see an even larger change in the ratio of phos- 

 phate esterified to acetaldehyde formed (from 0.7 to 5.1). That is, 

 the relative amount of H^Oo formed is higher at the higher oxygen 

 tensions. Most of these measurements had been completed before 

 we had an opportunity to study the paj^er of Warburg et al. (6) 

 on the chemical mechanism of photosynthesis. The data we had ob- 

 tained with Kg were very similar to those obtained in the Dahlem 

 laboratory with naphthoquinone sulfonate, though the methods used 



TABLE 4 

 Relation of Peroxide Production to Phosphorylation with K3 as Cofactor 



