DISCUSSION ON HYDROGEN TRANSPORT 



43 



(electron) transport system. I believe Mr. Haas has some experi- 

 mental data which have considerable bearing on this question. 



Erwin Haas, University of Chicago: 



For a long time the mechanism of respiration was studied only 

 by considering intermediary metabolites. A more direct approach 

 to that problem is now possible, since some of the respiratory 

 enzymes have become available in isolated form and since their 

 functional groups are known. 



cytochrome c 



cytochrome 

 reductase 



H 



GLUCOSE -6 -PHOSPHATE 

 FIGURE 1 



K = 10 



' K 10 



Figure 1 illustrates a part of the respiratory system which brings 

 about the reduction of cytochrome c by glucose-6-phosphate. The 

 components of the system are arranged in the order in which they 

 react; the details concerning their chemical structure are omitted. 

 Hydrogen or electrons from the glucose are passed on to the pyridine 

 nucleotide, thence to the alloxazine mononucleotide, and then to the 

 iron atom in cytochrome c. In each step a specific protein must be 

 present which, together with the prosthetic group, forms the active 



