What type of molecule is DNA?

DNA is a nucleic acid. Its full name, deoxyribonucleic acid, describes a long biological polymer built from repeating nucleotide units.

Each DNA nucleotide contains the sugar deoxyribose, a phosphate group, and one of four bases: adenine, thymine, cytosine, or guanine. DNA usually consists of two complementary strands twisted into a double helix, with the sequence of bases carrying genetic instructions.

Nucleic acid is the broad molecular category that includes both DNA and RNA. DNA is not a protein, lipid, or carbohydrate, although cells use DNA instructions to make proteins and DNA contains a sugar component. Alongside proteins, lipids, and complex carbohydrates, nucleic acids are one of the four major classes of biological macromolecules.

The molecule was first isolated in 1869, but its role as hereditary material was established much later. DNA is found in the chromosomes of cells and also occurs in structures such as mitochondria; some viruses use DNA as their genetic material.