DNA, or deoxyribonucleic acid, is a type of macromolecule known as a nucleic acid. Nucleic acids are essential for all known forms of life as they carry the genetic information necessary for the development, functioning, and reproduction of organisms.
DNA is composed of two long strands that form a double helix. Each strand is made up of repeating units called nucleotides. A nucleotide consists of three components: a sugar molecule (deoxyribose), a phosphate group, and a nitrogenous base. The four types of nitrogenous bases in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G). The sequence of these bases along the DNA strand encodes genetic information.
In summary, DNA is a nucleic acid, a macromolecule that stores and transmits genetic information in living organisms.