10 



A SYMPOSIUM ON RESPIRATORY ENZYMES 



isolated frog muscle or in the mammalian liver. Without going into 

 too much detail I will show you the table of consecutive inter- 

 mediary steps, neglecting the coenzymes concerned. As you see from 

 the double arrows in Figure 1, nearly all these reactions are re- 

 versible. The transformation of glucose-1-phosphate into glucose-6- 

 phosphate is also reversible, according to Cori's recent findings (22). 

 This reversibility is especially conspicuous for the oxidative step, 



CMM CO 



200 



150 



100 



40 MIN 



Figure 2. — Stoichiometric coupling reaction 

 Oxidation of phosphoglyceraldehyde is drawn upward. The points on the lines 

 were obtained by manometric measurement. The spectrographic measurements 

 were of dihydrocozymase (absorption maximum 340 mM-). 



