Nucleosides consist of a purine or pyrimidine base attached to a sugar through an energy-poor B-glycosidic bond.
Naturally occurring pentose sugars include ribose and 2-deoxyribose (Figure 6- 13).
When the sugar is attached to a base, the numbered carbon atoms of the sugar are given a prime designation to distinguish them from positions of atoms in the base.
The 2' of 2'-deoxyribose refers to C2 of the sugar.
Ribonucleosides contain ribose, and 2'-deoxyribonucleosides contain deoxyribose.