Discussion 



187 



The basis of the calculation is that it comes off equally from the two 

 in the glycolytic pathway. Of course, there are many difficulties in this. 

 The interpretation of our results is straightforward, based on the yields 

 from glucose labelled in positions 1 and 6. 



King : The limiting factor may not be the obvious one expected ; for 

 instance, the rates of the reactions in the glycolytic pathway may be 

 quite different from those in the pentose phosphate cycle. If so, will it 

 affect the calculation or interpretation? 



Dickens: It is unlikely that in the glycolytic-citric acid pathway it 

 would be at the same rate, because it goes through a whole chain of 

 about 30 reactions before it is entirely liberated, and many of these 

 may involve dilution of i*C, whereas in the pentose pathway it comes 

 off in the first step as ^^COg directly. 



