Cell Structure and Protein Synthesis 465 



may form not only proteins, but also nucleic acid, i.e. be capable of self-repro- 

 duction. However, it is necessary to bear in mind that the adequate conditions 

 for protein synthesis in these systems depend upon the interaction of practically 

 all the cell components, including, first of all, nuclei, mitochondria and hyalo- 

 plasm. Namely this, apparently, explains the fact that viruses, which also consist 

 of a protein and nucleic acid, can be reproduced only in living cells where they 

 are provided with the adequate conditions. 



We can conclude with the statement: protein synthesis is catalysed directly 

 by a chemical system representing a complex of protein and nucleic acid; this 

 system can be devoid of morphological organization form. The cell structure 

 at the present stage of evolution of life is necessary only for creating conditions 

 that make possible the synthesis of protein by nucleoproteins, i.e. first and fore- 

 most, for providing the latter with the necessary energy and materials for the 

 synthetic processes. 



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