# Glossary

## Deoxyribose

Deoxyribose is the specific form of monosaccharide that occurs in every nucleotide of DNA (hence the name "deoxyribose nucleic acid"). It differs from other sugars in that its chemical formula is not of the form $\mathrm{C}_x(\mathrm{H}_2\mathrm{O})_y$.

Like ribose, deoxyribose centers around a five-carbon ring, whose carbon atoms are numbered clockwise as 1', 2', 3', 4', and 5'. Also like ribose, deoxyribose is a chiral molecule, meaning that its mirror image can be made as well. The two different molecules are called D-deoxyribose and L-deoxyribose; D-deoxyribose is the molecule appearing in DNA, whereas its mirror image L-deoxyribose does not occur naturally.

Deoxyribose differs from ribose in that its 2' carbon is bonded to a hydrogen atom (H) instead of to a hydroxyl group (OH). See the figure below for an illustration of the chemical structure of deoxyribose.