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P.A. Levene's Contribution to the characteristics of DNA
This Biochemist discovered the basic structure of nucleotides that made up DNA. He discovered that nucleotides are subunits of nucleic acids and consist of Five-Carbon sugar, a phosphate group, and a nitrogenous base. And the two nucleic acids that were in living cells were DNA and RNA. -
Period: to
History Of DNA
This timespan are all of the disoceries of or about DNA from any scientists from 1920 to 1960 -
Fredrick Griffith's Contribution to the discovery of DNA
Fredrick Griffith held the first mayjor experiment that led to the discovery of DNA as a genetic material. In this experiment he studied to strains of bacteria, Streptococcus pneumoniae, he figured ou that this strain caused pneumonia and that it could be transformed into the other form. And with this experiment it set the search for identifying the transforming substance. -
Oswald Avery's Contribution to the discovery of DNA
Oswald Avery and his colleagues identified that molecule that transformed the R strain of bacteria into the S strain. At the end of the experiment they cocluded that the substance that did the transforming was DNA. But, his idea was not widely accepted and biologists still could not determine whether the proteins or DNA did the transfer of the genetic material. -
Erwin Chargaff's Contribution to the substances inside DNA
Chargaff found the amount of Adenine, Guanine, Thymine, and Cytosine in the DNA of many species. Chargaff's published data states that the amount of Gaunine equals the amount of Cytosine, and the amount of Adenine equals the amount of Thymine. This finding is known as Chargaff's Rule: C=G and T=A. -
Rosalinda Franklin's Contribution to the structure of DNA
Rosalinda, a Britsh chemist, used a technique called X-ray Diffraction that involved aiming X-rays at DNA molecules. When she joined the staff at King's College, that was were she took the famous photo with the X-ray machine and collected data that DNA's structure was a "Double Helix", or twisted ladder shape that is formed by two strands of nucleotides twisted around each other. The information that she provided was used in the definitin of DNA. -
Linus Pauling's Contribution to the structure of proteins
Linus Pauling's obssetion with chemistry led to his discovery of the structure of proteins that includes the structure of the most important chain: the Alpha Helix chain. He turned his attention to how polypeptide chains are folded. He figured out the structure by drawing a picture of the chain and folding it along several parallel lines soon making folds that formed a hydrogen bond that held the helical structure together. -
Alfred Hershey and Martha Chase's Contribution of the discovery of DNA
Hershey and Chase published results of an experiment that proved DNA is the transforming factor. In the experiment they used two components that made the experiment ideal for confirming that DNA is the genetic material which were bacteriophage, which was made of DNA and proteins. And the second thing were viruses that canno replicate themselves. In the end they used radioactive labeling to see what would happen to the DNA and the proteins which proved which one was the genetic material. -
Maurice Wilkins' Contribution to the discovery of the "Double Helix"
Wilkins in his own words was the "Third man of the Double Helix", which was his title for his autobiography that was published in 2003. And many think that he was not reconized enough that his research deserves. Wilkins was actually the first one to obtain an X-ray image of DNA that was taken at King's College were many of these scientists worked. And it was he who tought Francis Crick about DNA, and it was his photo that inspired James Watson and his research inspired other scientists aswell. -
James Watson and Francis Crick's DNA structure
Watson and Crick were working at the University of Cambrige, England. It was then they saw Franklin's Diffraction picture. Using both Franklin and Chargaff's data, Watson anf Crick measured the wicth of the helix and the spacing of the bases. Together they came up with the model of the "Double Helix" that complied with the other researchers rules and included some important features. -
WORK CITED
INFO ON: Fredrick Griffith, Oswald Avery, Hershey and Chase, P.A. Levene- Nucleotides, Rosalind Franklin – X-ray diffraction, Erwin Chargaff, James Watson-DNA structure, and Francis Crick-DNA structure: http://moodle.berea.k12.oh.us/mod/resource/view.php?inpopup=true&id=47397 INFO ON: Linus Pauling: http://www.brighthub.com/science/genetics/articles/21382.aspx
INFO ON: Maurice Wilkins: http://www.brighthub.com/science/genetics/articles/42027.aspx
