DNA is a polynucleotide with a double helix structure. It was discovered in 1953 by Watson and Crick.
It can be cut into nucleotide molecule components by careful hydrolysis. Each nucleotide is built up from a nitrogen-containing base, a phosphoric acid molecule and 2-deoxy-beta-D-ribose. The nitrogen-containing bases of DNA are adenine, thymine, guanine and cytosine.
Nucleotides attach and form polynucleotide chains. DNA consists of two polynucleotide chains, which are kept together by hydrogen bonds formed between complementary base pairs. Adenine can only attach to thymine, while guanine can only attach to cytosine, thus the base sequence of one chain determines the base sequence of the other, complementary chain.
The double helix is right-handed. The base pairs within the helix are covered with sugar-phosphate backbones consisting of deoxyribose and phosphoric acid. Each gene in the DNA defines a protein during biological protein synthesis, with the mediation of RNA molecules.
DNA carries genetic information in cells. In eukaryotes it is concentrated in the cell nucleus.
Deoxyribonucleic acid is mainly used in genetic engineering, for example in the modification of certain bacteria cells in order to produce important substances, such as insulin.