ABSTRACT
Deoxyribonucleic acid (DNA) takes central place in storage of genetic information. DNA molecule is a polymer consisting of two oppositely directed chains, which are twisted in the form of a right-handed double helix. Each chain is built from nucleotide units that contain sugarphosphate group and nitrogenous bases, nucleotides that are encoding genetic elements. The DNA structure contains four nucleotides: adenine A, guanine G, cytosine C and thymine T. The Sugar-phosphate group consists of 2-deoxyribose and phosphoric acid residues. DNA chain orientation is identifi ed by carbon atoms of 2-deoxyribose: (5′)CH2 and (3′)COH.
