Science As a Process

SCIENCE AS A PROCESS WHAT DO WE KNOW ABOUT DNA? HOW DID WE FIGURE IT OUT? http://profiles.nlm.nih.gov/CC/A/A/A/Z/_/ccaaaz~.jpg http://en.wikipedia.org/wiki/Rosalind_Franklin http://www.mun.ca/biology/scarr/Chase_&_Hershey_1953.jpg http://www.3quarksdaily.com/.a/6a00d8341c562c53ef0120a6194d2f970c-600wi http://www.time.com/time/time100/scientist/profile/watsoncrick.html

Archibald GARROD (1909) 1st to suggest genes dictate phenotypes through enzymes that catalyze specific reactions in cells Coined term inborn errors of metabolism Hypothesized that patients with alcaptonuria lack an enzyme in metabolic pathway ALCAPTONURIABlack urine disease Lack enzyme to break down alcapton Builds up in joints (osteoarthritis), heart valves, and kidney stones http://www.nexusediciones.com/images/alcaptonuria04.jpg

Excess excreted in urine Frederick GRIFFITH (1928) See the experiment Bacterial transformation of pneumonia bacteria in mice http://upload.wikimedia.org/wikipedia/en/thumb/f/f4/Griffithm.jpg/140px-Griffithm.jpg http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=glyco2&part=ch39&rendertype=figure&id=ch39.f1 Oswald AVERY, Colin MACLEOD, and Maclyn

MCCARTY (1944) Repeated Griffiths experiment but added enzyme to destroy different kinds of molecules. . . . DNA is the transforming molecule http://profiles.nlm.nih.gov/CC/A/A/A/Z/_/ccaaaz~.jpg George BEADLE and Edward TATUM (1940s) one gene-one enzyme

Neurospora bread mold mutants Each lacks different enzyme in biochemical pathway If add missing substance, mold is able to grow http://www.nauba-aloke-bangla.com/EBook/Projukti-o-Biggan/top100/Beadle_Tatum.jpg Experiment images from: Campbell and Reece AP Biology Alfred HERSHEY and Martha CHASE (1952) See their experiment

DNA = genetic code molecule http://osulibrary.oregonstate.edu/specialcollections/coll/nonspcoll/catalogue/portrait-hersheychase-600w.jpg https://www.msu.edu/course/lbs/333/fall/images/HERSHEY2.gif ROSALIND FRANKLIN and MAURICE WILKINS Analyzed DNA with X-ray crystallography to try and determine its structure 1953 - JAMES WATSON & FRANCIS CRICK used Rosalind Franklins X-ray crystallography mages (PHOTO 51) to come up with alpha helix

model for the structure of DNA http://en.wikipedia.org/wiki/Rosalind_Franklin http://www.time.com/time/time100/scientist/profile/watsoncrick.html http://www.pnas.org/content/101/52/17889/F1.medium.gif Matthew MESELSON and Franklin STAHL (1958) DNA copies by semi-conservative model

See their experiment http://en.wikipedia.org/wiki/File:DNAreplicationModes.png Images from: http://instruct1.cit.cornell.edu/courses/biog105/pages/demos/106/unit01/6.dnareplicationmodels.html MESELSON & STAHL Grew bacteria for many generations in radioactive (heavy) 15N . . . so all DNA is heavy Then grow in 14N, centrifuge as generations divide, and check to see where heavy DNA ends up

http://www.sumanasinc.com/webcontent/animations/content/meselson.html MESELSON & STAHL Can tell which model it is by the banding patterns of DNA molecules SO WHAT ? Provided evidence for SEMI-CONSERVATIVE REPLICATION MODEL

http://www.sumanasinc.com/webcontent/animations/content/meselson.html Telomeres protect DNA from being degraded Telomeres become shorter with each replication; shorter in older cells Telomerase enzyme lengthens telomeres Stem cells, germ cells making gametes, and cancer cells have increased telomerase activity 2009 Nobel Prize Physiology/Medicine

Discovery of Telomeres Jack Szostak Carol Greider Elizabeth Blackburn.

Recently Viewed Presentations

  • Sonnet no. 73 Presented Presented by: by: Leslie

    Sonnet no. 73 Presented Presented by: by: Leslie

    Sonnet no. 73 Presented by: Leslie Monagle That time of year thou mayst in me behold When yellow leaves, or few, or none do hang Upon those boughs which shake against the cold Bare ruined choirs where late the sweet...
  • www.nreeder.com

    www.nreeder.com

    Boolean Algebra. Boolean . algebra. is a set of rules first laid out by George Boole (1815-1864) for manipulating Boolean expressions. The rules are similar to the rules of regular algebra for manipulating numeric expressions. Our book lists these rules...
  • FOLG 2017 - How greater devolution can enhance governance ...

    FOLG 2017 - How greater devolution can enhance governance ...

    Edmund Burke: Little platoons - the germ of society and the first sub-division in society we belong to; Walter Lippman. We need to return to older forms of social organization (communitarian institutions) in order to address the problems caused by...
  • Today's Topics - Carnegie Mellon University

    Today's Topics - Carnegie Mellon University

    Transportation — CMU bus pass deactivates upon retirement. Seniors age 65+ are eligible to ride free when presenting a Medicare Card or a Pennsylvania Senior Citizen ID card. You may obtain the Pennsylvania Senior Citizen ID card at the Downtown...
  • Présentation La Banque Postale - e-MFP

    Présentation La Banque Postale - e-MFP

    Commentaire conclusif Depuis le 1er janvier 2008, l'Activité entreprises est animée et pilotée par la Direction des entreprises, des collectivités et des associations. Ainsi structurée, La Banque Postale accueille et accompagne 364 000 associations, 17 000 PME, 99 000 TPE,...
  • Physics 10 UCSD Work, Energy, Power, Momentum Measures

    Physics 10 UCSD Work, Energy, Power, Momentum Measures

    The total energy (in all forms) in a "closed" system remains constant This is one of nature's "conservation laws" Conservation applies to: Energy (includes mass via E = mc2) Momentum Angular Momentum Electric Charge Conservation laws are fundamental in physics,...
  • CS 4 this week Hw #10 due 11/19

    CS 4 this week Hw #10 due 11/19

    Visuospatial Skills. We use visuospatial skills in everyday life. Most importantly, visuospatial skills are a significant predictor of success in technical fields. Imagine graphics software for instance. Power to predict grades in technical courses equals that of math SAT scores...
  • Beats by Dre Headphones - WordPress.com

    Beats by Dre Headphones - WordPress.com

    Beats by Dre Headphones Drew Walters Preapproach Company or Organization background/ history Monster- Beats By Dr. Dre Noel Lee started Monster out of his garage 30 years ago and now his son Kevin Lee is the current owner Company policies...