{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Chapter 16 SG - Chapter 16 Frederick Griffith studied 2...

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 16 Frederick Griffith- studied 2 strains of strep; heat-killed pathogenic and mixed remains with nonpathogenic; some became pathogenic Transformation- change in genotype and phenotype due to assimilation of external DNA by cell (not cancerous change) Oswald Avery- purified molecules from heat-killed bacteria (Griffith’s) and tried transforming nonpathogenic; only DNA worked McCarty & MacLeod- along with Avery announced that DNA was the transforming agent; still doubted b/c little known about DNA Bacteriophage- bacteria-eating viruses that Hershey and Chase studied since because of its dual composition of DNA and protein Hershey & Chase- tagged T2 phage in 2 experiments, one with radioactive S (common in protein); radioactive P (common in DNA) a. Once tagged phages infected host cell ( E. Coli ) agitated host in blender and centrifuged mixture to form pellet b. 1 st experiment with S isotope that tested for protein floated at top, not mixed with bacterium protein doesn’t affect c. 2 nd experiment with P isotope sunk to bottom, mixed with the bacterium, which confirmed Avery’s, McCarty’s and MacLeod’s theory that DNA, not protein, transforms and is genetic material Erwin Chargaff- discovered similar ratios between nucleotide bases (i.e. humans have A=30.3%, T=30.3%, G=19.5%, C=19.5%) Chargaff’s Rule- any equivalences between the base pairs A&T and G&C
Image of page 1
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern