ABSTRACT
A nucleoside consists of a base covalently bonded to the 1-position of a pentose sugar molecule. In RNA the sugar is ribose and the compounds are ribonucleosides, or just nucleosides, whereas in DNA it is 2-deoxyribose, and the nucleosides are named 2-deoxyribonucleosides, or just deoxynucleosides. Base + sugar = nucleoside.
