FRITZ LIPMANN 



The chemical nature of the transformer catalysts which operate 

 on three 0.25-v, spans between the limits and -j-1.2 v. remains to be 

 considered. In analogy to what is known about the carbonyl com- 

 pounds, which in part could have the function of transformers on the 

 lowest potential level (9), the following generalization may be illus- 

 trative: The catalyst should offer opportunity to a phosphate molecule 

 to add onto a double bond. From the addition product a pair of 

 electrons is removed wherewith the energy-rich phosphate bond is 

 generated. This step should involve little or no energy loss. Ex- 

 change of adenylic acid hydrogen for the phosphate group now de- 

 livers 12 kcal. into the cell, and the residual product may be rehydro- 

 genated. This phase involves the refund of the delivered 12 kcal. 

 (0.25 v.) and must ultimately lead to a regeneration of the double 

 bond. Tentatively, the potential level around 0.1 v. may be assigned 

 to a carbonyl double bond. For the subsequent level around 0.5 v. 

 a C:C double bond would be suitable. Finally, a double bond of the 

 ascorbic acid type appears as a possibility for the upper level. A trans- 

 forming unit of the type outlined is charted arbitrarily for a C: C double 

 bond in scheme II. 



Scheme ii 

 A Catalytic Transformer of Electron Potential into Phosphate Bond Energy 



O/R-CATALYST 

 HC-H I 



"2'-' ^ • V 3 -^H SYSTEM 



/ V /^ Eo= 0.45 V. 



HCH HC H-ad 



I II + 



HCOH CO-POJ- 



WATER 

 SYSTEM 



Eo=0.2V. ..Zfll u A ^ UTILIZA- 



METABOLITE HjC ad ~- P0i"-^-TION 



t 



C:0 = 0.25 V. 



With slight modification it is applicable to any double bond of a C:X 

 type, X being, for example, :0 or :NH. The essential feature of the system is 

 a shuttling between addition of water and of phosphate to the double bond. 

 Starting from the bottom and moving clockwise, we distinguish four steps of 

 the cyclic process. First, by hydrogenation of the water system the transformer is 

 loaded with about 0.25 v. per mole, at least. Second, the reduced water 



146 



