1 / 10

Biologists on Genetics Erwin Chargaff (1905-2001)

Biologists on Genetics Erwin Chargaff (1905-2001). Relative quantities of the nitrogen bases found in DNA. Background. About Erwin Chargaff. Born in Austria on August 11, 1905 Receive a doctorate degree of Chemistry from the University of Vienna in 1928

fuller-knight
Télécharger la présentation

Biologists on Genetics Erwin Chargaff (1905-2001)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Biologists on Genetics Erwin Chargaff(1905-2001) Relative quantities of the nitrogen bases found in DNA

  2. Background

  3. About Erwin Chargaff • Born in Austria on August 11, 1905 • Receive a doctorate degree of Chemistry from the University of Vienna in 1928 • 1944 - Study of DNA and its four chemical bases - adenine, cytosine, guanine and thymine • Using chromatography technique • Discover amounts of adenine and thymine were equal, as were the amounts of cytosine and guanine

  4. The 4 nitrogen bases

  5. The 4 nitrogen bases - Purines • Consist of a six-membered and a five-membered nitrogen-containing ring, fused together • Adenine = 6-amino purine • Guanine = 2-amino-6-oxy purine

  6. The 4 nitrogen bases - Pyrimidines • Have only a six-membered nitrogen-containing ring • Uracil = 2,4-dioxy pyrimidine • Thymine = 2,4-dioxy-5-methyl pyrimidine • Cytosine = 2-oxy-4-amino pyrimidine

  7. Chargaff's first parity rule • Stated that purines pair with pyrimidines, specifically A with T and C with G • E.g ACGATGCCGTA • With pairing between complementary bases in the "top" and "bottom" strands 

  8. Chargaff's second parity rule • % of A approximately equals % of T; % of G approximately equals % of C for single strands of DNA

  9. Cluster rule • Stated that pyrimidines often occur in runs or clusters, and hence on the complementary strand purines do likewise

  10. GC rule • Stated that (G+C)% is constant within a species, but often differs between species.

More Related