149 



TABLE 6-3: Components of the Nucleic Acids (Linkage at *] 



"Bases" (B) 



Purines 



NH 2 



A: adenine y NH 



G: guanine 



OH 



N K 



Pyrimidines 

 NH, 



C: cytosine N 



o n; 

 h 



o 



U: uracil HN 



°V 



O 



T: thymine H *f 



o A < 



H* 



CH 



Carbons 3 and 5 link to phosphates; carbon 1 links to the base. 



Nucleic Acid Backbone 



