Genie and Non-genic Parts of the Chromosome 39 



that in a long molecule many permutations are possible, and (quot- 

 ing) "it therefore seems likely that the precise sequence of the 

 bases is the code which carries the genetical information." 



In a semipopular paper (1954) Crick explains it thus: "Such 

 an arrangement can carry an enormous amount of information. If 

 we imagine that the pairs of bases correspond to the dots and dashes 

 of the Morse code, there is enough DNA in a single cell of the human 

 body to encode about a thousand large textbooks. What we want to 

 know, however, is just how this is done in terms of atoms and 

 molecules. In particular, what precisely is it a code for? As we 

 have seen the three components of living matter — protein, RNA and 

 DNA — are probably all based on the same general plan. Their back- 

 bones are regular and the variety comes from the sequence of the 

 side groups. It is therefore very natural to suggest that the sequence 

 of the bases of the DNA is in some way a code for the sequence of 

 the amino acids in the polypeptide chains of the proteins which the 

 cell must produce." 



It follows that if the order of bases in one chain is given, that on 

 the other chain is obligatory, and complementary. This makes it 

 possible that each single chain if separated from its partner can 

 act as a template (two complementary templates), thus supplying 

 for the first time a model of a template in terms of atoms and residues. 

 In detail, the hydrogen bonds are broken, the two chains uncoil and 

 separate, each chain serves as a template to the companion chain, 

 producing two identical new molecules (without the need of a 

 negative and positive, as in the old template concept). It is sup- 

 posed that after the H-bond breakage, the single chain takes up a 

 heHcal configuration. If free nucleotides are available in quantity 

 from time to time, the base of a free nucleotide will join one of the 

 bases already formed on the chain. A polymerization of the mono- 

 meres to form a new chain is possible only if the resulting chain can 

 accomplish the correct structure. A special enzyme may mediate the 

 polymerization, or the single chain may act as an enzyme. This is 

 clearly a molecular structure capable of self-duplication, and, if self- 

 duplication is the main characteristic of the genie material, we may 

 conclude that the DNA molecule is the genie material. Watson and 

 Crick clearly think so and adduce further facts and deliberations. 



It can be calculated that the two molecular chains twist in 

 34 A distances and accomplish about 150 turns per million molecular 

 weights. The visible coiling of the chromonema may reflect similar 

 processes on a molecular level. "Although it is difiicult at the moment 



