FORMATION OF AMINOACIDS 



473 



of an atom of oxygen, on the other hand from the ketonic 

 acid by the addition of a molecule of ammonia. This acid 

 would, if conditions are favorable for oxidation, catabolize 

 to ketonic acid by the cleavage of ammonia and thereafter by 

 the introduction of an atom of oxygen to the next lower acid ; 

 if, however, conditions favorable for reduction prevail, 

 would be reduced to aminoacid. We know already, however, 

 that an aminoacid can be converted into an oxyacid by a 

 typical hydrolytic deaminizing process. 



Following this line of thought recently Embden has suc- 

 ceeded, 52 by experimentally perfusing the liver of the dog 

 with blood to which ammonia salts of various a -ketonic acids 

 have been added, in obtaining their corresponding a -amino- 

 acids : 



62 G. Embden with E. Schmitz and K. Kondo (Frankfurt a. M.), Biochem. 

 Zeitschr., 29, 423, 1910; 38, 393, 407, 1912. 



