25 April 1953

Francis Crick and James Watson publish “Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid” describing the double helix structure of DNA.

The double helix structure of DNA is the shape that the DNA molecule takes. DNA, or deoxyribonucleic acid, is the genetic material that carries the instructions for the development, functioning, and reproduction of all living organisms.

The double helix structure is made up of two strands of nucleotides that are twisted together in a helical shape. Each nucleotide is composed of a sugar molecule, a phosphate group, and a nitrogenous base. The nitrogenous bases in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G).

The two strands of the double helix are held together by hydrogen bonds between the nitrogenous bases. Specifically, adenine always pairs with thymine, and cytosine always pairs with guanine. This base-pairing rule is known as complementary base pairing.

The double helix structure of DNA is important because it allows for the faithful replication of the genetic material during cell division. The complementary base pairing ensures that the sequence of nucleotides in the original DNA molecule is accurately preserved in the newly synthesized DNA molecule. Additionally, the double helix structure protects the genetic information from damage and allows for the efficient storage and retrieval of genetic information.