6 2 



THE FORMATION 01- PROTElDS IN PLANT-CELLS. 



a transitory product, found when the conditions of finishing the 

 process of protein-synthesis are not complete. To these con- 

 clusions we are led by the circumstances under which asparagin 

 appears in shoots, and disappears again. 



When sugar participates in the formation of proteids from 

 asparagin, it evidently yields the carbon to make up the deficiency ; 

 this function, however, would not be required if aspartic acid 

 were used ; the proportion of the number of atoms of 

 N : C is in albumen i : 4 



in aspartic acid 1 : 4 

 in asparagin 1 : 2 



(in tyrosin 1 : 9, in leucin 1 : 6). 



Several considerations (see Chapt. VIII) make it highly 

 probable, that the formation of protein compounds consists in a 

 rapidly proceeding condensation process, in a certain degree 

 analogous to the formation of sugars from formic aldehyde. I} 

 To render, however, such a process possible, asparagin would 

 best be converted into the di-aldehyde of aspartic acid, a reduc- 

 ing process whereby glucose very probably would have to furnish 

 the necessary hydrogen : 



CONH, COH 



I I 

 CH 2 CH, 



I +4H = I +NH 3 +H 2 0. 



CH.NH 2 CH.NH, 



I I 

 COOH COH 



Asparagin. Aspartic aldehyde. 



The conditions in the living cells would not permit for a 

 moment these products of reductions in a free state, and in 

 presence of glucose the ammonia set free would be transformed 

 at once into organic combinations, most probably into another 

 molecule of aspartic aldehyde ; thus asparagin and glucose 

 would yield directly 2 mol. of this aldehyde, which may be 

 expressed by the following equation : 



1) I have been the first to show that formic aldehyde will by condensation yield 

 true sugars, and the first to prove beyond a doubt, that such a synthetical sugar is 

 capable of alcoholic fermentation. No sophistry can disprove these facts. 

 Compare Journ. f. prakt. Chem. 33, 332; Ber. d. Deutsch. Chem. Ges. 20, 142 and 

 3042 ; Ibid. 22, 477 and 481 ; Lar.dw. Versuchstat. 41, 132. 



