667 



Martin Gibbs 



a hexose sugar labeled predominantly in carbon atoms 3^ ^ (0-3^ 

 C-k) . Subsequently isotope entered the a and 3 carbons of 3-PGA 

 and Crl, C-2, C-5, C-6 of the hexose. Similarity in distribution 

 of C between both halves of hexose provided evidence that the 

 conversion of 3-KjA to hexose occurred via the reversal of the 

 Embden-Meyerhof pathway. Using>the Leuconostoc mesenteroides 

 technique, Gibbs and Kandler^ •^' reported that glucose isolated 

 from starch and sucrose produced during short periods of photo- 

 synthesis possessed an asymmetric distribution of C^^ rather than 

 the predicted symmetrical distribution. Many explanations such 

 as transaldolase exchange reactions and pool dilution of the 

 dihydroxyacetone-P have been offered to circumvent this unex- 

 pected finding. 



The absence of aldolase in extracts of blue-green algae and 

 the report of Handler^ ^^^ that the distribution of C"^^ in the 

 products formed during photosynthesis in C Op by Anacystis 

 nidulans was similar to those obtained with Cnlorella, an alga 

 which contains aldolase, prompted an examination of the distribu- 

 tion pattern of C in A. nidulans polysaccharide. 



Table 1. DISTRIBUTION OF C-l4 IN POLYSACCHARIDE GLUCOSE 

 FORMED DURING PHOTOSYNTHESIS USING A. nidulans and C pyrenoidosa 



Relative specific activity of the carbons of glucose on the basis 



of C-4=100 



Ik 



Table I shows the asymmetric pattern of distribution of C 



