Nucleotides

Nucleotides are formed by condensation of a pentose sugar, a cyclic nitrogen base and one to three phosphoric acids. They are basic units of nucleic acids and constitute part of information transfer and energy transfer systems of the cells.

Nucleoside is a condensation product of a pentose sugar and a nitrogen base. The linkage between the two is a glycosidic bond (–C–N–C–) formed between carbon atom 1’ of pentose sugar with nitrogen atom 1 of pyrimidine or nitrogen atom 9 of purine. Depending upon the pentose sugar involved, nucleosides are of two types, ribonucleosides and deoxyribonucleosides.

Various nucleosides are:

Adenosine (A) Ribose + Adenine

Guanosine (G) Ribose + Guanine

Cytidine (C) Ribose + Cytosine

Uridine (U) Ribose + Uracil

Deoxyadenosine (dA) Deoxyribose + Adenine

Deoxyguanosine (dG) Deoxyribose + Guanine

Deoxycytidine (dC) Deoxyribose + Cytosine

Deoxythymidine (dI) Deoxyribose + Thymine