Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
In the context of DNA, sugars refer to deoxyribose molecules. Deoxyribose is a five-carbon sugar that forms a part of each nucleotide in DNA.
Related terms
Ribose: This is another type of sugar found in RNA (ribonucleic acid). Unlike deoxyribose, ribose has an additional oxygen atom attached to one of its carbon atoms.
Pentose Sugar: Deoxyribose and ribose both belong to a class of sugars called pentoses because they have five carbon atoms.
Sugars combine with phosphates and nitrogenous bases to form nucleotides, which are the building blocks that make up DNA and RNA. Each nucleotide contains a sugar molecule, phosphate group, and nitrogenous base.