In 1951, when the American biologist James Watson arrived at the laboratory, it was known that the mysterious nucleic acids, especially DNA, played a central role in the hereditary determination of the structure and function of each cell. Watson convinced Crick that knowledge of DNA's three-dimensional structure would make its hereditary role apparent. Using the X-ray diffraction studies of DNA done by Wilkins, Watson and Crick were able to construct a molecular model consistent with the known physical and chemical properties of DNA. The model consisted of two intertwined helical (spiral) strands of sugar-phosphate, bridged horizontally by flat organic bases. Watson and Crick theorized that if the strands were separated, each would serve as a template (pattern) for the formation, from small molecules in the cell, of a new sister strand identical to its former partner. This copying process explained replication of the gene and, eventually, the chromosome, known to occur in dividing cells. Their model also indicated that the sequence of bases along the DNA molecule spells some kind of code "read" by a cellular mechanism that translates it into the specific proteins responsible for a cell's particular structure and function.
By 1961 Crick had evidence to show that each group of three bases (a
codon) on a single DNA strand designates the position of a specific
amino acid on the backbone of a protein molecule. He also helped to
determine which codons code for each of the 20 amino acids normally
found in protein, and thus helped clarify the way in which the cell
eventually uses the DNA "message" to build proteins. From
1977 he held the position of distinguished professor at the Salk Institute
for Biological Studies in San Diego, Calif. His book Of Molecules and
Men (1966) discusses the implications of the revolution in molecular
biology. What Mad Pursuit: A Personal View of Scientific Discovery was
published in 1988.
Main Page | About Us | All text is available under the terms of the GNU Free Documentation License. Timeline of Nobel Prize Winners is not affiliated with The Nobel Foundation. External sites are not endorsed or supported by http://www.nobel-winners.com/ Copyright © 2003 All Rights Reserved.