Rosalind ElsieFranklin . She is an outstanding English scientist who had important contributions to the understanding of DNA structures , as well as relevant research on the microstructures of carbon and graphite, and this work was the basis for her doctorate in physical chemistry .
Summary
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- 1 First steps
- 2 Work life
- 3 Rosalind Dusts Watson And Crick’s Arguments
- 4 Rosalind repeats her studies
- 5 Publication of Rosalind’s studies
- 6 Opinion on Franklin’s work
- 7 Most important medical achievement of the 20th century
- 8 Death
- 9 Posthumous controversy
- 10 Source
- 11 external links
First steps
He graduated from Cambridge University in 1941 , but not before overcoming parental opposition. He did fundamental studies of the microstructures of carbon and graphite and this work was the basis for his Ph.D. in physical chemistry, which he obtained from Cambridge University in 1945 .
Laboral life
After Cambridge, she spent three productive years ( 1947-1950 ) in Paris at the Laboratoire de Services Chimiques de L’Etat, where she performed X-ray diffraction techniques. In 1951 , she returned to England as a research associate in John Randall ‘s laboratory at King’s College , Cambridge . For Rosalind it was an opportunity to apply her knowledge to biology, and Randall’s lab was at its best. In Randall’s lab she crossed paths with her and Maurice Wilkins , even though they were both referring to theDNA . Unfortunately, the misogyny and competition brought the relationship into permanent conflict with Wilkins. He had been working on DNA for a long time and had taken the first relatively clear crystallographic diffraction picture of it. Wilkins had been the first to recognize nucleic acids in it and was unwilling to compete internally.
Rosalind powders Watson and Crick’s arguments
At that time the dehydrated form of the molecule (form A) was known, which did not suggest a helical form. Rosalind concentrated first on interpreting diffraction patterns using Patterson’s laborious formulas. The first images obtained in London with dehydrated DNA were revealed in Cambridge. Watson had had occasion to attend Franklin’s November 1951 lecture on the progress of his research. Quickly, with Francis Crickthey set to the task of imagining its structure and for this, they worked mainly with atomic scale models. This first attempt would end in resounding failure.
Watson and Crick invited Franklin and Wilkins to Cambridge to make their proposal known to them. This consisted of a helical model with three chains. Magnesium ions held the phosphates together and towards the periphery the pentoses and the nitrogenous bases. Rosalind Franklin pulverized their arguments. The amount of water in the model did not correspond to that in the diffraction studies. The phosphates and thus the “ backbone ” of the moleculethey had to be on the outside of it. There was actually no consistent evidence that the structure was helical.
The well-known English phlegm surely prevented the catastrophe. Anyway, the rumor reached the head of the lab: Sir Lawrence Bragg , who decided to forbid Watson and Crick from continuing their studies on DNA . Cunning prevailed: James Watson concentrated on the study of tobacco mosaic virus. This has RNA as one of its fundamental constituents. Elucidating this structure would allow him to get closer to DNA and in the process deepen his knowledge in crystallography .
Rosalind repeats her studies
Meanwhile, during 1952 Rosalind Franklin repeated the crystallographic studies with different degrees of hydration. On hydration the diffraction was completely different (form B). As we now know, the DNA strands move away from each other and take on their native shape.
Publication of Rosalind’s studies
In early 1953 Wilkins showed Watson one of Franklin’s crystallographic pictures of the DNA molecule , when Watson saw the picture the solution became apparent to him and the results were published in an article in Nature almost immediately. Without Rosalind’s permission, Wilkins first showed them – the images of form B (hydrated) – to James Watson and later a report from Rosalind Franklin to Sir John Randall .was given to Watson and Crick. Francis Crick had worked on deciphering what the helical structures of proteins would look like in crystallography images. And that was exactly what he had in front of him in the Franklin report.
Furthermore, the reflection of 3.4 Å in the meridian implied that this was the distance between the nucleotides of the same DNA chain. Applying these measurements to shape A and correcting for the shrinkage and density of the molecule, there was only room for two nucleotides in each transverse plane. If that was so, the most logical thing is that the chains were also two. In their book The Ten Greatest Discoveries in Medicine (Editorial Paidós), Meyer Friedman and Gerald W. Friedland recount the story of Rosalind Franklin, but it is in the book byAnne Sayre Rosalind Franklin and DNA (WW Norton & Co., New York, 1975 ) where a correct and complete version of the story can be read.
Opinion on Franklin’s work
James Watson refers to Franklin as “Rosy” and wonders “what it would be like if she took off her glasses and did something different with her hair.” In the epilogue to his book he admits that his initial impressions of her “were often wrong” and warned “some years too late of the struggles an intelligent woman must face…” Francis Crick , in his retrospective of those years, What Mad Pursuit , approached the subject somewhat differently… there were “irritating restrictions – no coffee allowedin one of the rooms reserved for men only – but these were relatively trivial or so it seemed at the time.” [from the book by Thomas F. Lee (The Human Genome Project. Breaking the genetic code of life, Editorial Gedisa) , in the bestseller The Double Helix]
Most important medical achievement of the 20th century
Considered the most important medical achievement of the 20th century , the DNA double helix model paved the way for the understanding of molecular biology and genetic functions; antecedents that have led to the establishment, in these days, of the “complete” sequence of the human genome. Rosalind Franklin obtained an X- ray diffraction photograph that unmistakably revealed the helical structure of the DNA molecule. That image, known today as the famous photograph 51 , was a crucial experimental support for the American researcher [[James Watson]] and the British Francis Crick to establish, in 1953, the famous hypothesis of the “double helix” that is characteristic of the molecular structure of DNA ([[deoxyribonucleic acid]]), for which in 1962 , together with Maurice Wilkins , they were awarded the Nobel Prize in Physiology and Medicine.
Death
Franklin died prematurely, of ovarian cancer, in 1958 in London . In all likelihood, this illness was caused by the repeated exposures to radiation during his investigations. Rosalind Franklin she died prematurely in 1958 in London, at the age of 37, a victim of ovarian cancer. In all likelihood, this illness was caused by the repeated exposures to radiation during her investigations. Her invaluable contribution to this discovery was not recognized either during the crystallographer’s lifetime or posthumously, although little by little the true story of her is beginning to be known.
posthumous controversy
The conditions that she had to endure as a woman at Cambridge and certain derogatory words from James Watson make the award of the Nobel Prize for Physiology or Medicine only to Watson, Crick and Wilkins in 1962 appear as a grievance , when in fact their death had already taken place. death. Her peers, including Watson, famous for his caustic references to his colleagues, repeatedly expressed their personal and intellectual respect for her. In any case, Rosalind Franklin deserves the place she has come to occupy as an icon of the advancement of women in science.
