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Period: to
People of DNA
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P.A. Levene
Levene determined the basic structure of necleotides that make up DNA. cited- biology text book page 329 -
Fredrick Griffith
discovered DNA as genetic material. Studied 2 strains of bacteria which causes pneumonia.
cited- biology text book page 326 -
Oswald Avery
identified the molecule that transformed the R strain of bacteria into the S strain. He isolated different macromoleccules such as DNA, proteins, lipids from killed S cells. Then he exposed live R cells to the macromolecules seperatley. Avery concluded that when the S cells in Griffith's experiment died DNA was released. cited- biology text book page 327 -
Erwin Chargaff
Chargraff analyzed the anount of adenine, guanine, thymine, cytosine in the DNA of various species. He found that the amount of guanine nearly equals the amount of cytosine, and the amount of adenine nearly equals the amount of thymine in a species. the finding is known as Chargraffs rule, C=G and T=A cited- text book page 329 -
Hershey and Chase
they published results to their experiments that provided definite evidence that DNA is the transforming factor. they used a technique called radioactive labeling to trace the fate of the DNA and protein as the bacteriophages infected bacteria and reproduce. cited- biology text book page 327-238 -
Rosalind Franklin
She produced X-ray cyristallography pictures of BDNA. Watson and Crick used the X-ray to build the double helix. She was able to calculate the basic demensions of the DNA molecule cited- http://www.dnai.org/timeline/index.html -
Maurice Wilkins
Wilkins was working on a technique called X-ray diffraction. A technique that involved aiming X-rays at DNA molecules. He worked with Crick to determine that DNA was a double helix. cited- biology text book page 330 -
Linus Pauling
Proposed triple stranded helix structure. he had the phosphate groups of each DNA strand facing into the helical core. he had forgot the negative charges of the oxygen atom. in each phosphate group. the charges would repel making it impossibe for the molecule to hold together. He had gotten it wrong. cited- http://www.dnai.org/timeline/index.html -
James Watson
worked with Crick on finding the double helix. showed that each nucleotide building block of DNA is made up of a phosphate group linked to deoxyribose sugar. cited- biology text book page 330 -
Francis Crick
he used Chargaff's and Franklin's data to build a double helix.
proposed central dogma and adaptor hypothesis. showed that each nucleotide building block of DNA is made up of a phosphate group linked to deoxyribose sugar. cited- biology text book page 330
