208 ABIOGENIC ORGANIC-CHEMICAL EVOLUTION 



Stances of high-energy phosphorus compounds such as adeno- 

 sine triphosphoric acid (ATP) was the decisive event deter- 

 mining the transition from the inanimate to the animate 

 state. In this he is starting from the hypothesis that the 

 adenylic acid systems which were developed primarily and 

 which are now widely distributed in living nature would, 

 under the conditions present in the primitive ocean, open 

 up the possibility of the formation of proteins, inasmuch as 

 the energy required for the synthesis of polypeptides is com- 

 paratively small and could be provided at the expense of a 

 single high-energy bond. Blum considers that an adenylic 

 system could also have formed the basis for the development 

 of nucleic acids. 



The author himself admits that the details of the process 

 \vhich he has put forward are very vague, and he bases his 

 opinion solely on the phenomena which take place in living 

 things. It does, indeed, seem more and more probable that 

 the energy needed for the synthesis of the polypeptide bonds 

 of protein molecules is provided in the living organism 

 through the agency of high-energy phosphorus compounds.^"' 

 In particular, according to H. Borsook^^" the first stage in 

 this synthesis is the activation of the carboxyl groups of free 

 amino acids at the expense of ATP, either directly or through 

 coenzyme A. The synthesis of nucleic acids in living proto- 

 plasm takes place in just the same way, at the expense of 

 high-energy bonds. In this process, according to H. M. 

 Kalckar^^^ phosphorylated ribose (ribose - 1 - phosphate) ex- 

 changes its phosphate radical for a purine or pyrimidine 

 base with the formation of the corresponding nucleoside. ^^^ 



However, R. Zahn^" considers that first there must sud- 

 denly have been formed polyphosphoric acid, which is even 

 now present in a number of organisms. ^^* 



Starting from this assumption and proceeding by analogy 

 with the reactions which occur in living things, L. Roka^^^ 

 has drawn the following hypothetical picture of the forma- 

 tion of nucleic acid in the waters of the primaeval ocean : 

 the macromolecule of polyphosphoric acid which arose there 

 reacted with glyceraldehyde to form polyglyceraldehyde phos- 

 phate, which, in later reactions, combined with acetaldehyde. 

 This scheme is based on the observation of the biosynthesis 



