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Alfred hershey

Alfred hershey. By: Jamie Newman, Fairus Tefery , & Tavasha Amador. About Alfred “The Bacteriologist/Geneticist” . Born on December 4, 1908 Studied at Michigan State College Obtained his B.S. in 1930, and Ph.D., in 1934

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Alfred hershey

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  1. Alfred hershey By: Jamie Newman, FairusTefery, & Tavasha Amador

  2. About Alfred “The Bacteriologist/Geneticist” • Born on December 4, 1908 • Studied at Michigan State College • Obtained his B.S. in 1930, and Ph.D., in 1934 • Following, he was given the position of research assistant at the Department of Bacteriology of Washington University, in St. Louis, Missouri. • Promoted to instructor in 1936, assistant professor in 1938, and associate professor in 1942.

  3. Hershey’s Kiss • Worked with Italian microbiologist Salvador Edward Luria and German physicist Max Ludwig Henning Delbruck performing experiments with bacteriophages, viruses that infect bacteria. • They organized the "Phage Group," a team of bacteriophage researchers who met every year to discuss their work and advances. • In 1946, they observed “when two different strains of bacteriophages have infected the same bacteria, the two viruses may exchange genetic information.” • They then produce offspring with different infective natures than either parent carried. • This was the first example of genetic recombination in viruses.

  4. “THE PHAGE GROUP”

  5. “The Blender Experiment” • Hershey and American geneticist, Martha Chase, performed their famous "blender experiment." • Using a kitchen blender, they separated the protein coating from the bacteriophage's nucleic acid core. • They injected nucleic acid into the bacterial cell and found that the acid caused multiplication and replication and spread of genetic information, not its protein components. • This proved that genes are made of the nucleic acid DNA.

  6. Martha Chase & Hershey (1953)

  7. Want More Hershey? • Later, Hershey's research helped the development of vaccines for mumps, measles and polio. • Hershey was awarded the 1969 Nobel Prize in physiology (or medicine), along with Luria and Delbruck, for their discovery on the replication of viruses and their genetic structure. • It was said that he retired from active research in 1972, but was a constant figure around the lab until his death on May 22, 1997.

  8. Sources (Including Pictures) http://library.thinkquest.org/20465/hershey.html http://nobelprize.org/nobel_prizes/medicine/laureates/1969/hershey-bio.html http://www.wired.com/images/article/full/2007/09/Alfred_Hershey_580x.jpg http://4.bp.blogspot.com/_DZH2cmCoois/RuhDKdFgteI/AAAAAAAADCg/Zpvwte-jWjg/s400/Nobel_Laureates_1969_Delbruck_Hershey_Luria.bmp http://www.uic.edu/classes/bios/bios100/summer2003/Chase__Hershey_1953.jpg

  9. O.T AVERYOctober 21, 1877 – 2 February 1955 Jasmine René, Shonnee Pryor, Jazmyn Washington Block C (Biology HCP) Ms. Queen March 3, 2010

  10. Early Life • 1877 Born October 21, in Halifax, Nova Scotia, son of Joseph Francis Avery and Elizabeth Crowdy Avery. • 1900 Awarded B. A. degree from Colgate University. • 1904 Awarded M. D. degree from Columbia University College of Surgeons. • 1904 -1907 Practiced general surgery. • 1907 Bacteriologist with Hoagland Laboratories in Brooklyn, NY; became associate director. • 1923 Made a member of the faculty of the Rockefeller Institute (biomedical research). • 1943 Retired as emeritus member(a professor who of the Rockefeller Institute. • 1943-1948 Continued bacteriological research as emeritus member. • 1949 Retired to Nashville, Tennessee. • 1955 Died in Nashville; buried in Mt. Olivet Cemetery.

  11. Contributions To Discovery of DNA • Material in which the genetic information is encoded is DNA and not protein or carbohydrates. • Advanced biological and medical science, providing knowledge and insight that could be applied to the study of all living things. • Identified DNA as the "transforming principle" in the early 1940s. • In 1928, Fred Griffith performed the first experiment which suggested that protein was not the genetic material. Oswald Avery followed up on Fred Griffith's experiment in the following decade.

  12. Contributions To Discovery Of DNA (continued). • In 1944, at the Rockefeller Institute, he showed that the activity of the then-unknown material responsible for transformation was not affected by protein-destroying enzymes. But the activity was stopped by DNA-destroying enzymes. This demonstrated the role of DNA in transformation, because he showed that DNA had the instructions for making the capsule of the S type.  • Avery and his colleagues discovered that DNA is the nucleic acid that stores and transmits the genetic information from one generation to the next.

  13. Frederick Griffith Michelle Denkins Karima Alvarez Ms.Queen HCPBiology March 1, 2010

  14. Griffith’s Early Years Born in 1879 in Hale, in Cheshire, England. He lived a very quiet and private life. Work did not become known until his death. Was a microbiologist. He attended Liverpool University. His older brother, A. Stanley Griffith was also a microbiologist. After graduating from Liverpool University in 1901.

  15. Griffith’s Job He worked for the Liverpool Royal infirmary, the Thompson Yates Laboratory, and the Royal Commission on Tuberculosis. In 1910 he began working for the English government, in what would later be called the Ministry of Health.

  16. Griffith’s Studies Griffith researched many kinds of microorganisms, but his most important work dealt with pheumococcus. The bacteria that can cause pneumonia. All types of these bacteria can theoretically cause disease, but some types (such as Type III) cause disease more readily than others (such as Type II).

  17. Griffith’s Research When Griffith began his work, he knew that the difference in virulence was due to a polysaccharide coating, or capsule, on the Type III organisms which protected the bacteria from the host’s immune system. The Type II pneumococcus lacked the “capsule” that protected Type III. Bacterial colonies with capsules are called (S) colonies, and ones without capsules are called (R) colonies.

  18. Griffith Passes Away Little is known about Griffith’s private life except that he enjoyed skiing, walking, and vacations at his country cottage in Sussex. Griffith and a longtime colleague at the Ministry of Health, the bacteriologist William M. Scott, were killed in 1941 during the bombing of London when a bomb blew up the building in which they worked.

  19. MARTHA CHASE BY TAYLOR SHERRELL KYRA CLEMENT-RALEIGH ASIA WILKERSON

  20. BIOGRAPHY • Born in Cleveland, Ohio in 1927. • She attended USC. • She was an American geneticist famously known for being • Suffered from dementia: memory loss, problems with functioning • Married biologist Richard Epstein • Martha Chase, a scientist who helped conduct a famous DNA experiment, died on Aug. 8 of pneumonia. She was 75.

  21. CHASE’S EXPERIMENT • Worked with biologist Alfred Hershey. • When bacteria was radioactive, they were allowed to infect nonradioactive bacteria, all the infected cells became radioactive and many of the radioactivity was passed on to the next generation of bacteria. • When the bacteria was infected, the virus coats removed. Radioactivity was not detected in the infected cells. • From these experiments, it was clear that the DNA of the bacteria is injected into the bacterial cell while the protein component remains outside. • DNA is able to direct the formation of new virus particles complete with protein coats. • Therefore, genes are DNA.

  22. Diagram of experiment.

  23. Contributions! • Geneticists Alfred Hershey and Martha Chase publish the findings of their so-called blender experiments, which conclude that DNA is where life's hereditary data is found. • Hershey would subsequently share the 1969 Nobel Prize in Physiology or Medicine for his work in discovering the properties of DNA. But Chase, who served as Hershey's lab assistant during his experiments and whose name appears on the paper, was snubbed.

  24. Rosalind Elsie Franklin Pioneer Molecular Biologist Jonna German Rebeka Garcia GennesisEuceda Bio HCP Block C March 1,2010

  25. Early Life • Rosalind Elsie Franklin was an intelligent chemist who was instrumental in providing clues to the structure of DNA and confirmed the Watson-Crick DNA model. Born in London England on July 25, 1920 she was the second of five children in her Anglo-Jewish family. She attended St. Paul’s school for girls which was one of the few that focused on preparing its girls for careers in chemistry and physics, not just for marriage. She excelled in math and science and eventually learned to speak Italian and sufficient German.

  26. Secondary Education In 1938 she enrolled in Newnham College at Cambridge University At Cambridge she majored in physical chemistry In 1942 she began work with the British Coal Utilization Research Association For the next four years she worked to clarify the micro structures of various coals and carbons, from this she learned why some were more permeable by water, gases and solvents, and how heating and carbonization affected permeability Franklin was the first to identify and measure these microstructures and this fundamental work made it possible to classify coals and predict their performance accurately

  27. Achievements • 1941-42 :Researched the the kinetics of polymerization reaction at the Physical Chemistry Laboratory, Cambridge • 1942-46: Research on collodial properties of coals and cokes • 1947-51: Directed a research group in x-ray diffraction studies of carbon at the Labortaoire Central des Services Chimiques de l’Etat in Paris • Assembled an x-ray diffraction laboratory at King’s College, London, to research the structure of DNA, where she discovered DNA has two forms(A&B) • In1953 she was invited to direct research on x-ray diffraction studies of plant viruses particularly the tobacco mosaic virus • Determined the configuration of TMV and the location of its RNA

  28. "Science and everyday life cannot and should not be separated. Science, for me, gives a partial explanation of life. In so far as it goes, it is based on fact, experience, and experiment. . . . I agree that faith is essential to success in life, but I do not accept your definition of faith, i.e., belief in life after death. In my view, all that is necessary for faith is the belief that by doing our best we shall come nearer to success and that success in our aims (the improvement of the lot of mankind, present and future) is worth attaining." --Rosalind Franklin in a letter to Ellis Franklin, ca. summer 1940 …In the fall of 1956 she was diagnosed with Ovarian cancer, two years later on April 16th 1958 she died in London at the age of 37…

  29. Sources Cited(including pictures and images) www. Sdsc.edu/..franklin.html www.accessexcellence .org/AB/BC… www.profiles.nlm.nih.gov www.blog.educastur.es www.static.howstuffworks.com www.rosalindfranklin.edu/

  30. Linus Pauling NaimaBakari Angela Campos NelinieCayetano

  31. Who is Linus Pauling? • An American Quantum Biochemist and participated in the “DNA Race”. • He studied ray diffraction of crystals. • He won a Nobel Peace Prize in Chemistry in 1958.

  32. A Biography • He was born February 28, 1901 in Portland, Oregon and died on August 19, 1994 in Big Sur, California at the age of 93. • Was a chemist and one of the first scientists to work in the fields of quantum chemistry, molecular biology, and orthomolecular medicine. • Was awarded two Nobel Peace Prizes in chemistry and peace.

  33. His New Mission • Traveled to Europe on a Guggenheim fellowship scholarship awarded in 1926. • Studied under German physicist Arnold Sommerfeld, Danish physicist Niels Bohr, and Austrian physicist Erwin Schrödinger. • Became interested in quantum mechanics and tried to apply it to his chosen field of interest such as the electronic structure of atoms and molecules.

  34. Contraptions • Pauling made another trip to Euorpe and learned about the use of electrons in diffraction studies in the summer of 1930. • Built an electron diffraction machine and used it to study molecular structure of a large number of chemical substances. • Introduced electronegativity in 1932. • Created the “Pauling Electronegativity Scale.”

  35. Biological Stuff • In the mid-1930’s, Pauling studied the structure of hemoglobin. • After various forms of extensive research with other scientists, Pauling came to the conclusion that DNA was a Triple Helix. • He was soon proved wrong and noted his mistakes that we made.

  36. Contribution to the Discovery of DNA • During the 1940s, Pauling worked on sickle cell anemia a search for a helical structure of DNA and solution to protein architecture. • He concluded that sickle celled anemia was a disease. • Linus Pauling proposed that DNA was a helix, but as a triple helix, not as a double helix.

  37. Experiments in DNA • Linus Pauling performed many experiments, but his experiments in X-ray crystallography helped contribute to the discovery of DNA. • X-ray crystallography is used to determine the arrangement of atoms within a crystalline molecule.

  38. Citations • Wikipedia. N.p., n.d. Web. 1 Mar. 2010. <http://www-tc.pbs.org/wgbh/nova/photo51/images/pict-1951photo51.jpg>. • Wikipeda. N.p., n.d. Web. 1 Mar. 2010. <http://en.wikipedia.org/wiki/Linus_Pauling#Biological_molecules>.

  39. Erwin Chargaff By: Cinthya Benitez, Mitzuky Orellana, Natalie Sylvestre Ms. Queen Biology HCP (Block C) March 1, 2010

  40. Erwin Chargaff the Biochemist • Born in Czernowitz, Austria on August 11, 1905 • Attended University of Vienna • Received his doctorate on 1928 • Worked in the Colombia University College of Physicians and Surgeons in 1935

  41. Chargaff’s contributions to the discovery of DNA • Contributed to the advancement of the double helix structure of DNA through Chargaff's Rules • Contradicts the tetranucleotide hypothesis-- stating that DNA was composed of numerous repeats of a GACT

  42. Chargaff’s Contribution to the discovery of DNA A=30.9% and T=29.4%; G=19.9% and C=19.8% Adensine= Thymine Cytosine= Guanine

  43. Chargaff’s Experiment • Erwin Chargaff noticed a pattern in the amounts of the nucleotide bases: adenine, guanine, cytosine, and thymine • Took samples of DNA from different cells • Separated the bases from each other • Exposed the bases to ultaviolet that was absorbed • Determined how much of a base exsisted by measuring the amount of light they absorbed • Found that the amount of adenine was almost accurate to the amount of thymine, and that the amount of guanine was almost accurate to the amount of cytosine

  44. Erwin Chargaff’s Awards • Charles Leopold Mayer Prize in 1963 • Heineken Prize in biochemistry in 1964 • Honorary degrees from Columbia University and the University of Basel in 1976

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