MECHANISMS OF OXIDATION [N TISSUES 

 HN CO HN CO 



CO C NH + = CO C NH 



;CH 



HN C N 



II / 

 HN C NH 



CO 



Thus a whole series of different ferments effecting dissimilar changes 

 may be required to .convert even such a relatively simple body as a 

 purine base into the end-products of its metabolism in the body. 



