Ribose vs Deoxyribose
Introduction
The 2 types of sugars present in the nucleic acids - RNA and DNA - are Ribose (RNA) and Deoxyribose (DNA).
Structure
Deoxyribose is a Pentose sugar that has one less oxygen atom than Ribose. The chemical formula of Deoxyribose is C5H10O4 and the chemical formula of Ribose is C5H10O5. The molecular structure of 2 - deoxy - D - ribose is that is has a hydrogen at the second carbon rather than a hydroxyl group.
Why DNA has Deoxyribose and RNA has Ribose?
DNA has deoxyribose sugar rather than a ribose sugar since it is more stable. Deoxyribose contains an hydrogen which doesn't make the pentose susceptible to hydrolysis, like the hydroxyle group would. The Hydroxyl group has a ability to act as a nucleophile. A nucleophile is a chemical species that forms bond by donating an electron pair.