ENERGY TRANSFORMATION 389 



bacteria, there is no ordinary respiration from organic substances, as 

 shown by Meyerhof : 



The whole process of respiration can thus be presented by the following 

 reactions: 11 



(NH 4 ) 2 C0 3 + 3 2 = 2 HN0 2 + C0 2 + 3 H 2 + 147.2 Cal. (1) 



or 



2 NH 3 (acq.) + 3 2 = 2 HNO2 + 2 H 2 + 156.8 Cal. (2) 



78.4 calories are liberated per 1 mol of ammonia oxidized 



2 HN0 2 + 2 = 2 HN0 3 + 37.6 Cal. 

 18.8 calories are liberated per 1 mol of nitrite oxidized. (3) 



For the synthesis of its protoplasm, the organism obtains its carbon 

 from the C0 2 of the atmosphere: 



C0 2 + H 2 = i (C 6 H 12 0«) + 2 - 113 Cal. 



Winogradsky, 12 however, suggested that no oxygen is separated in 

 the respiration of the nitrite forming bacteria and no carbohydrates 

 are formed ; the ammonia may react directly with C0 2 giving urea : 



NH 2 

 H 2 C0 3 + 2 NH 3 = CO-/ + 2 H 2 

 NH 2 



The urea can be used directly for the synthesis of proteins; the 

 carbohydrate required for the synthesis of amino acids may be formed 



11 The heats of reaction in all autotrophic and a few heterotrophic processes 

 have been recalculated, using Landolt-Bornstein's Physikalisch-chemische Tabel- 

 len. 5te Aufl. Berlin. 1923; the data for the greater part of the heterotrophic 

 processes have been taken from Kruse's book. 



12 Winogradsky, S. Sur les organismes de la nitrification. Compt. Rend. 

 Acad. Sci., 110: 1013-1016. 1890. 



