Francis Crick.

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Francis Crick.
I

INTRODUCTION

Francis Crick (1916-2004), British biophysicist and cowinner of the 1962 Nobel Prize in physiology or medicine. Crick shared the prize with American biologist James D.
Watson and British biophysicist Maurice Wilkins for their discoveries about the structure of deoxyribonucleic acid (DNA), the molecule that transmits genetic information
from generation to generation.

II

EARLY EDUCATION AND RESEARCH

Francis Harry Compton Crick was born in Northampton, England. His father owned a footwear factory and encouraged Crick's early interest in scientific experiments.
Crick attended the local grammar school and won a scholarship to Mill Hill School in North London at the age of 14. At University College, London, he studied physics.
After graduation in 1937, Crick briefly pursued his doctoral degree studying the properties of water under high temperatures and pressures. His studies were
interrupted by World War II (1939-1945), during which Crick worked for the scientific service of the British Admiralty, helping to design magnetic and acoustic mines.
After World War II, Crick decided his interests lay in biology. There were two general areas he wished to pursue: what he later described as "the borderline between the
living and nonliving" and neurobiology. He decided to initially concentrate on the first goal, studying the chemical components that form the basis of living things. Thus,
in 1947 he returned to school to study biology at the Strangeways Research Laboratory at Cambridge University.

III

IDENTIFYING THE STRUCTURE OF DNA

In 1949 Crick moved to the Cavendish Laboratory at Cambridge University to pursue his doctoral degree. Working under British physicist and Nobel laureate Sir William
Lawrence Bragg, Crick studied the structure of proteins using X-ray diffraction. X-ray diffraction provides X-ray patterns of a molecule's chemical structure. He
eventually moved to a unit of the Medical Research Council (MRC), a publicly funded laboratory located at Cambridge University. At MRC, Crick found himself in talented
company. He worked under the guidance of Austrian-born British biochemist Max Perutz and alongside British chemist John Kendrew, two future Nobel laureates. Crick
initially studied the structure of hemoglobin, a red, iron-rich protein that carries oxygen in the blood. It was not long, however, before Crick became more interested in
studying the structure of DNA.
In 1951 Watson joined Crick's laboratory at MRC. Crick and Watson shared the same passionate desire to determine the structure of DNA and, over the next two years,
they worked together on the problem. American biochemist Linus Pauling had earlier shown success in building scale models to identify the structure of proteins. Crick
and Watson decided to use that approach to study DNA. At the time, Wilkins and British chemist Rosalind Franklin at King's College, London, were using X-ray diffraction
analysis to study the DNA molecule. Crick and Watson applied the diffraction studies created by Wilkins and Franklin to their own research.
After a few missteps, Crick and Watson used the X-ray diffraction patterns created by Franklin to develop a three-dimensional model for the structure of DNA. This
model depicted DNA as two complementary strands twisted into a double helix.
In 1953 Crick and Watson published their findings in the science journal Nature. Because of their work, scientists were able to understand and describe living things for
the first time in terms of the structure and interaction of molecules. Recognized as one of the most significant discoveries of the 20th century, the identification of the
structure of DNA affects practically every scientific discipline in the life sciences.

IV

OTHER CONTRIBUTIONS TO GENETICS

Crick received his Ph.D. from Cambridge University in 1953. He then worked briefly with Watson on the structure of viruses. But he eventually returned to the study of
DNA and his findings led to rapid advances in genetics. He and his coworkers determined how the order of bases, chemical subunits on the DNA structure, act as a code
to determine the sequence of amino acids that make up proteins. With South African-born British geneticist Sydney Brenner, Crick identified that codons, groups of
three bases, provide instructions for the creation of all 20 amino acids.
Crick made two sweeping theories that have stood the test of time. In his adaptor hypothesis, he theorized that small molecules of ribonucleic acid (RNA) and enzymes
work as intermediaries between DNA and amino acids during protein synthesis. Initially met with skepticism in the science community, the theory was eventually proven
correct with the discovery of transfer RNA and adaptor enzymes. Crick also theorized that the flow of genetic information is from DNA to RNA to protein, and that
genetic information cannot flow the other way, from protein to RNA to DNA. This theory has been tested repeatedly since Crick discussed it at a meeting of the Society
of Experimental Biology in 1957, and it is now called the central dogma, a crucial principle of molecular biology.

V

LATER RESEARCH

In 1977 Crick moved to the Salk Institute of Biological Studies at La Jolla, California, where he pursued his early interest in neurobiology, studying how the brain
functions. He also worked on questions related to the origins of life on Earth. Never afraid to announce a controversial theory, in 1981 Crick wrote Life Itself, in which he
argued that life on Earth could have originated in microorganisms that arrived from elsewhere in the universe.
Other books by Crick include Molecules and Men (1966) and The Astonishing Hypothesis (1994). He also authored more than 130 scientific papers.
In addition to the Nobel Prize, Crick was awarded the Albert Lasker Award for Basic Medical Research, the Award of Merit from the Gairdner Foundation, and the Prix
Charles Leopold Meyer of the French Academy of Sciences. Crick was a member of the U.S. National Academy of Sciences, the Royal Society, the French Academy of
Sciences, and the Irish Academy.

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