polynucleotide
otherwise
nucleic acid
(rus. полинуклеотид otherwise нуклеиновая кислота)
—
polymer molecule consisting of nucleotides.
Description
Polynucleotides are biopolymers, nucleic acids (from Lat. nucleus) formed by nucleotides, which consist of a nitrogenous base, a carbohydrate residue and a phosphate group. Nucleotides are linked via phosphoric acid residue (phosphodiester bond). Polynucleotides formed by ribonucleotides are called ribonucleic acid (RNA); deoxyribonucleotides form deoxyribonucleic acid (DNA). They differ, not only by the type of carbohydrate residue, but also by the type of nitrogenous bases. Nucleic acids are comprised of adenine, cytosine and guanine, as well as thymine (DNA) and uracil (RNA). When referring to polynucleotides, abbreviations for nucleotide residues are numbered in 5 '→ 3' direction, i.e. from left to right. Interaction of the phosphate group of a nucleotide with the 3'-OH-group of another nucleotide leads to the formation of a dinucleotide with a phosphodiester bond. Such a dinucleotide carries a free phosphate group at the 5'-end, and a free OH-group at the 3'-end. Therefore, a new mononucleotide can be linked to the dinucleotide with another phosphodiester bond. Oligonucleotides and, ultimately, the polynucleotides are formed in this way. In a cell, the synthesis of nucleic acids is carried out by enzymes, with the original DNA molecule as a template. Polynucleotides of specific nucleotide composition can be used as structural elements of DNA nanostructures or components of biogenic nanoparticles.
Illustrations
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Polymer DNA chain fragment. |
Authors
- Boris S. Naroditsky
- Lyudmila N. Nesterenko
- Vladimir P. Shirinsky
Sources
- Oligomers// Chemical encyclopedia . V. 3 (in Russian). — Мoscow: Bol'shaja Rossijjskaja ehnciklopedija, 1992. 375–377 pp.
- Rees A., Sternberg M. From Cells to Atoms: An Illustrated Introduction to Molecular Biology. — Blackwell Science Inc, 1984. — 75 pp.