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Thursday, September 29, 2011

British scientist who contributed to the discovery of the molecular structure of DNA


Rosalind Elsie Franklin (25 July 1920 – 16 April 1958) was a British biophysicist and X-ray crystallographer who made critical contributions to the understanding of the fine molecular structures of DNA, RNA, viruses, coal and graphite.The DNA work achieved the most fame because DNA (deoxyribonucleic acid) plays essential roles in cell metabolism and genetics, and the discovery of its structure helped scientists understand how genetic information is passed from parents to children.


Franklin is best known for her work on the X-ray diffraction images of DNA which led to discovery of DNA double helix. Her data, according to Francis Crick, were "the data we actually used" to formulate Crick and Watson's 1953 hypothesis regarding the structure of DNA.Franklin's X-ray diffraction image confirming the helical structure of DNA were shown to Watson without her approval or knowledge. Though this image and her accurate interpretation of the data provided valuable insight into the DNA structure, Franklin's scientific contributions to the discovery of the double helix are often overlooked. Unpublished drafts of her papers (written just as she was arranging to leave King's College London) show that she had independently determined the overall B-form of the DNA helix and the location of the phosphate groups on the outside of the structure. However, her work was published third, in the series of three DNA Nature articles, led by the paper of Watson and Crick which only hinted at her contribution to their hypothesis.


After finishing her portion of the DNA work, Franklin led pioneering work on the tobacco mosaic and polio viruses. She died in 1958 at the age of 37 from complications arising from ovarian cancer.Franklin was born in Notting Hill, London into an affluent and influential British Jewish family.Her father was Ellis Arthur Franklin (1894–1964), a London merchant banker and her mother was Muriel Frances Waley (1894–1976); she was the elder daughter and second of the family of five children. Her father's uncle was Herbert Samuel (later Viscount Samuel) who was Home Secretary in 1916 and the first practising Jew to serve in the British Cabinet. He was also the first High Commissioner (effectively governor) for the British Mandate of Palestine. Her aunt Helen Carolin Franklin was married to Norman de Mattos Bentwich, who was Attorney General in the British Mandate of Palestine.She was active in trade union organisation and women's suffrage, and was later a member of the London County Council.

Franklin was educated at St Paul's Girls' School and North London Collegiate School where she excelled in science, Latin and sports.Her family was actively involved with a Working Men's College, where Ellis Franklin, her father, taught electricity, magnetism and the history of the Great War in the evenings and later became vice principal. Later Franklin's family helped settle Jewish refugees from Europe who had escaped the Nazis.

In the summer of 1956, while on a work-related trip to the United States, Franklin first began to suspect a health problem—she found she could no longer do up her skirt because of a lump around her abdomen.An operation in September of the same year revealed two tumours in her abdomen.After this period and other periods of hospitalization, Franklin spent time convalescing with various friends and family members. These included Anne Sayre, Francis Crick, his wife Odile, with whom Franklin had formed a strong friendship,and finally with the Roland and Nina Franklin family where Rosalind's nieces and nephews bolstered her spirits. Franklin chose not to stay with her parents because her mother's uncontrollable grief and crying upset her too much. Even while undergoing cancer treatment, Franklin continued to work, and her group continued to produce results, seven papers in 1956 and a further six in 1957. In 1957, the group was also working on the polio virus and had obtained funding from the Public Health Service of the National Institutes of Health in the United States for this.

At the end of 1957, Franklin again fell ill and she was admitted to the Royal Marsden Hospital. She returned to work in January 1958 and she was given a promotion to Research Associate in Biophysics.She fell ill again on March 30 and died on April 16, 1958, in Chelsea, London, of bronchopneumonia, secondary carcinomatosis and carcinoma of the ovary. Exposure to X-ray radiation is sometimes considered a possible factor in her illness.Other members of her family have died of cancer, and the incidence of "female" cancer is known to be disproportionately high among Ashkenazi Jews. Her death certificate read: A Research Scientist, Spinster, Daughter of Ellis Arthur Franklin, a Banker.

 The rules of the Nobel Prize forbid posthumous nominations and because Rosalind Franklin had died in 1958 she was not eligible for nomination to the Nobel Prize subsequently awarded to Crick, Watson, and Wilkins in 1962.The award was for their body of work on nucleic acids and not exclusively for the discovery of the structure of DNA.By the time of the award Wilkins had been working on the structure of DNA for more than 10 years, and had done much to confirm the Watson-Crick model. Crick had been working on the genetic code at Cambridge and Watson had worked on RNA for some years.

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