Nucleotides Constituents of Nucleic Acids

A variety of organisms collectively synthesize an enormous number of different biomacromolecules (Berg et al, 2002 Voet and Voet, 2004 Garrett and Grisham, 2(X)5), whose great range of physicochemical and biochemical characteristics are derived mainly from the varied properties of their constituent monomer molecules. Therefore some aspects of the monomer chemistry are discussed in this chapter. 

The structure and properties of nucleic acids are affected and inherited from the general stracture characteristics of their monomer molecules and nucleotides (Blackburn and Gait, 1996 Harmon et al, 1978 Saenger, 1984). Nucleotides are the phosphate esters of nucleosides, which are components of both ribonucleic add (RNA) and deoxyribonucleic acid (DNA). All nucleotides are constructed from three components  

In ribonucleotides, the pentose is the o-ribose while in deoxyribonucleotides, the sugar is 2 -deoxy-D-ribose. The nitrogen base of the planar, heterocyclic molecule derived from purine or pyrimidine is linked to Cl of the sugar residue. The phosphate group may be bonded to the C3 or C5 of a pentose to form its 3 -nucleotide or its 5 -nucleotide respectively. In nucleic acids, the purine and pyrimidine bases of nucleotides serve solely as information symbols for the coding of genetic information. 

Biomacromolecules, by C. Stan Tsai Copyright 2007 John Wiley Sons, Inc. 

The choices available to nitrogen bases are the keto-enol and amine-imine equihbrium  

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NUCLEOTIDES CONSTITUENTS OF NUCLEIC ACIDS 17 TABLE 2.1 pKa values for bases in nucleosides and nucleotides... 

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