CHAPTER 3 



Deoxypentose Nucleoproteins and Their 

 Prosthetic Groups^ 



1 . INTRODUCTION 



Some time in 1800, the German poet Kleist wrote a letter to a 

 friend in which he mentioned an idea that had occurred to him 

 when passing through an arched gateway: "Why, I thought, does 

 the vault not collapse, though entirely without support? It stands, 

 I replied, because all the stones want to fall down at the same 

 time." Similarly, one could say that the cell lives because all its 

 components desire to die simultaneously. They survive, in other 

 words, by getting into each other's way. 



That branch of chemistry that is, among many other things, 

 entrusted with conducting a traffic survey of the Uving cell is 

 comparatively young. At the present time, it is true of cytochem- 

 istry, as essentially of many other sciences, that we can recognize 

 the very general and the very special; but what lies between — and 

 that is the greater part of the world — is completely obscure. 



In trying to compare the state of biochemistry, for example, 

 of fifty years ago with that of today, one could use a metaphor. 

 In the old times, the knowledge of biology was perhaps similar 

 to what could be made out in a very large, very dark house. 

 Many objects could be more felt than seen with equal dimness, 

 once the eyes got used to the darkness; and scientists were con- 

 scious of the limiting conditions under which they worked. In 

 our time, however, a few very powerful and very narrow beams 

 of Hght have been thrown into a few corners of this dark house. 



* Reprinted with permission from Symposia Soc. Exptl. Biol., 9 (1955) 



32-47. 



References p. 60 



