Deoxyribonucleic Acid (DNA)
DNA stands for deoxyribonucleic acid, it is located in the nuclei of cells which make up the body. DNA is quite often referred to as one of the building blocks of the body.. It is made up of four bases known as: •
James Watson, Francis Crick, Maurice Wilkins, Rosalind Franklin Crick and Watson, together with Maurice Wilkins, won the 1962 Nobel Prize in physiology or medicine for their 1953 determination of the structure of deoxyribonucleic acid (DNA) this was one of the most significant scientific discoveries of the 20th century. James Watson and Francis Crick discovered the molecular structure of DNA model of the structure resembled a twisted rope ladder. They proposed that the DNA molecule consisted of two spirally wound, helical chains. Rosalind Franklin (1920–1958)
Franklin had established herself as a world expert in the structure of graphite and other carbon compounds. Rosalind Franklin had discovered that DNA could crystallize into two different forms, an A form and a B form. John Randall (was a physicist who led the King's College London team which worked on the structure of DNA) gave Franklin the A form and Wilkins the B form, assigning them each the task of elucidating their molecular structure. Wilkins and Franklin used X-ray crystallography as a technique to set out their experiment. The steps to this technique are simple, you just need to expose a crystal to X-ray in order to produce a diffraction pattern. Once you have a pure enough diffraction patterns it is possible to then reconstruct the positioning of the atom within the molecules that make up the basic unit also referred to as the unit cell. DNA is a very complex molecule that's why it took scientists a long time to learn to do this. Many impure diffraction patterns were formed during this due to the mix up of the A and B forms of DNA. This made it hard to interpret. Rosalind and Franklin's discovery of the A and B...
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