4. Ribonucleotide Phosphate unit + Ribose + one base unit from A, G, C, or U.
5. Deoxyrlbo nucleotide Phosphate unit + Deoxyribose + one base from A, G, C or T.
6. Nucleoside Ribose- / deoxyribose + one base unit from A, G, C, Tor U.
DNA and RNA
Nucleic acid is polynucleotide, present in the living cells or bacterial cells having no nucleus and in viruses having no cells.
( i) DNA Deoxy ribonucleic acid. DNA + H2O → Phosphoric acid + deoxyribose + A, G, C, T
( ii) RNA Ribonucleic acid RNA + H2O → Phosphoric acid + Ribose + A, G, C, U
Structure of DNA
It consists of two polynucleotide chains, each chain form a right handed helical spiral with ten bases in one turn of the spiral. The two chains coil to double helix and run in opposite direction. These are held together by hydrogen bonding.
Structure of RNA
It is usually a single strand of ribonucleotides and take up right handed helical conformation. Up to 12000 nucleotides constitute an RNA.