CHAPTER 1 



Chemical Specificity of Nucleic Acids and Mechanism 

 of Their Enzymic Degradation"^ 



1. INTRODUCTION 



The last few years have witnessed an enormous revival in in- 

 terest for the chemical and biological properties of nucleic acids, 

 which are components essential for the life of all cells. This is 

 not particularly surprising, as the chemistry of nucleic acids 

 represents one of the remaining major unsolved problems in 

 biochemistry. It is not easy to say what provided the impulse for 

 this rather sudden rebirth. Was it the fundamental work of Ham- 

 marsten^ on the highly polymerized deoxyribonucleic acid of 

 calf thymus? Or did it come from the biological side, for instance, 

 the experiments of Brachet^ and Caspersson^? Or was it the 

 very important research of Avery^ and his collaborators on the 

 transformation of pneumococcal types that started the avalanche? 

 It is, of course, completely senseless to formulate a hierarchy 

 of cellular constituents and to single out certain compounds as 

 more important than others. The economy of the living cell 

 probably knows no conspicuous waste; proteins and nucleic acids, 

 lipids and polysaccharides, all have the same importance. But 

 one observation may be offered. It is impossible to write the 

 history of the cell without considering its geography; and we 

 cannot do this without attention to what may be called the 

 chronology of the cell, i.e., the sequence in which the cellular con- 



* This article is based on a series of lectures given before the Chemical 

 Societies of Zurich and Basle (June 29th and 30th, 1949), the Societe de 

 chimie biologique at Paris, and the Universities of Uppsala, Stockholm, 

 and Milan. (Reprinted with permission from Experientia, 6 (1950) 201-209). 



References p. 23 



