PROTEINS 



6 7 



ysis of ingested protein of animal or vegetable origin. Experi- 

 ments, however, by Abderhalden and by Grafe and Schlapfer and 

 others indicate that the nitrogen of food protein may in part be re- 

 placed by ammonium salts. Experiments by Osborne and others 

 also indicate amino acid synthesis by animals. 



Important data regarding the decomposition products of the protein 

 molecule are given in the tables which follow. 



COMPARISON OF THE DECOMPOSITION PRODUCTS OF PROTAMINES, AND 



OTHER PROTEINS. 



When we examine the formulas of the principal members of the 

 crystalline end-products of protein decomposition we note that they are 



: Zeit. physiol. Chem., 44, 347, 1905. 

 2 Osborne and Guest: Jour. Biol. Chem., 9, 425, 1911. 



3 Abderhalden, Kossel and others. 



4 Abderhalden, Fischer, Morner and others. 



6 Fischer, Levene and Aders: Zeit. physiol. Chem., 35, 70, 1902; also Levene and 

 Beatty: Ibid., 49, 252, 1906. 



6 Abderhalden: Zeit. physiol. Chem., 37, 484, 1903. 



7 Osborne andLiddle, Am. Jour. Physiol., 26, 295, 1910. 



* This unique and important protein has probably been more carefully analyzed 

 than any other. 



