

THE PROTEINS 



Thus tyrosine under the action of bacteria of putrefaction may split u 

 into ammonia and oxyphenyl propionic acid. 



OH.C 6 H 4 .CH 2 .CHNH 2 .COOH + H 2 : 

 HO.C 6 H 4 .CH 2 .CH 2 .COOH + NH 3 



Under the action of yeasts an amine may become an alcohol. 

 C 5 H U .NH 2 + H 2 = C 5 H n .OH + NH 3 



(amylamine) (amylalcohol) 



On the other hand, the effect of the bacteria may be to split off carbon dioxide 

 from the amino-acids. Thus, the diamino-acid, lysine, 

 CH 2 NH 2 CH 2 NH 2 



CH 2 CH 2 



CH 2 becomes CH 2 pentamethylene di amine. 



CH 2 CH 2 



CH.NH 2 CH 2 NH 2 



COOH 



Tyrosine becomes p. oxyphenylethylamine, a substance having marked 

 physiological effects, and an important constituent of ergot. Phenylalanine 

 C 6 H 5 .CH 2 .CH.NH 2 .COOH, becomes phenylethylamine C 6 H 5 .CH 2 .CH 2 .NH 2 . 

 These reactions are therefore of value in determining the exact grouping of the 

 atoms in the more complex of the proximate constituents of the proteins. 



Since all the known disintegration products of the proteins belong to the 

 class of amino-acids, it may be of value to point out some of the distinguishing 

 features of this class of bodies. 



PROPERTIES OF AMINO-ACIDS. An amino-acid is derived from an 

 organic acid by the replacing of one atom of hydrogen by the amino group 

 NH 2 . Thus from the acids, 



acetic acid propionic acid 



CH CH 3 



COOH CH 



we may obtain the mono-amino-acids, 



amino-acetio acid alanine or a.amino-propionic acid 



CH 2 NH 2 CH 3 



COOH CH.NH 2 



COOH 



