Genomics Information Resources

DeoxyriboNucleic Acid (DNA) is the genetic material of the cell, making up chromosomes found within the nucleus. The DNA itself is divided into operative units called genes that carry instructions for making up the living organism (hair colour in humans etc). Each gene serves as a code for a particular protein. Since organisms are made up of proteins, the genes determine what the individual features of that organism will be.

X-ray diffraction photographs, taken by Maurice Wilkins, of the DNA fibres showed a distinctive X shape. He took this to be a characteristic of a helix structure. In 1951, Watson and Crick began work to unravel the structure of DNA. It was widely believed that DNA was a feature of the nucleus of every living cell, and that DNA may control heredity, but their work sought to further explain DNA's function by mapping its structure. Watson and Crick used molecular models to devise a structure that would account for Wilkins' diffraction photographs as well as prevailing chemical evidence. They devised the double helix, in which all the blocks fitted together without overlapping or squashing, and which accounted for stabilisation by hydrogen bonds. In 1962 Wilkins, Watson and Crick all received the Nobel Prize for medicine in recognition of their achievements in the field of DNA research and X-ray crystallographic imaging.