The Watson-Crick Model of DNA (1953)
Deoxyribonucleic Acid (DNA) is a double-stranded,
molecule. It consists of two sugar-phosphate backbones on the outside, held
together by hydrogen bonds between pairs of nitrogenous bases on the
inside. The bases are of four types (A, C, G,
& T): pairing always occurs between A & T, and C & G. James Watson (1928 - ) and
Francis Crick (1916-2004) realized that these pairing rules
meant that either strand contained all the information necessary to
make a new copy of the entire molecule, and that the order of
bases might provide a "genetic code".
Watson and Crick shared the Nobel Prize in 1962 for their discovery, along with Maurice Wilkins (1916-2004), in whose lab Rosalind Franklin (1920-1958) had produced crystallographic evidence for a helical structure. Crick went on to do fundamental work in molecular biology and neurobiology. Watson become Director of the Cold Spring Harbor Laboratory, and headed up the Human Genome Project in the 1990s.