ABSTRACT
Nucleic acids play an important role in all biological systems. They help in storing the genetic information and in protein biosynthesis. There are two types of nucleic acids: ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). Both DNA and RNA are biopolymers in which the repeating monomer units are called nucleotides. The heterocyclic base is either a pyrimidine or a purine. Pyrimidines are the compounds having the same parent heterocyclic nucleus – the pyrimidine. Hydrogenation of pyrimidine and its derivatives under acid conditions gives 1, 4, 5, 6-tetrahydropyrimidine which has the properties of an aliphatic amidine. The purine ring system is one of the most important units present in living systems, but as in the case of pyrimidines the parent compound has not been found in nature. Nucleotides polymerise to form long chain molecules known as polynucleotides which actually constitute the nucleic acids.
