1 / 12

Structure of DNA

Structure of DNA. SBI 4U November 2 nd , 2012. Discovery of the Molecular Structure!. Fredrick Miescher : Disovered “ nuclein ” located within the nucleus of cells – today called nucleic acid

lefty
Download Presentation

Structure of DNA

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. Structure of DNA SBI 4U November 2nd, 2012

  2. Discovery of the Molecular Structure! • Fredrick Miescher: Disovered “nuclein” located within the nucleus of cells – today called nucleic acid • Scientists in 1940’s were aware of DNA being the molecule of life, but did not know what it looked like! • Franklin and Wilkins  used x-ray diffraction to study structure

  3. Discovery of the Molecular Structure … • Franklin’s famous x-ray diffraction photo allowed Watson & Crick to discover the double-helical structure of DNA

  4. The Basics • DNA is a polymer - polynucleotide • Nucleotides are the monomer units • Each nucleotide consists of: a deoxyribose sugar, a phosphate group and a nitrogeneous base • Source of variation  nitrogeneous bases

  5. 4 Bases in DNA • Adenine • Thymine • Guanine • Cytosine

  6. Purines & Pyrimidines • Two classes of nitrogen bases • Purine: Nitrogenous base with two-carbon nitrogen rings (Adenine & Guanine) • Pyrimidines: One carbon-nitrogen ring (Cytosine and Thymine)

  7. Basic Structure • Double-stranded helix • Ladder analogy • Sugar-phosphate backbone, bases in the middle

  8. Bonding between Molecules • Phosphate of one nucleotide bonded to the sugar of the next nucleotide – covalent bonding • Phosphodiester bond: A bond between 1 phosphate group and 2 sugar groups  link 2 nucleotides together

  9. Bonding Between Molecules, continued … • Hydrogen bonding: Between the phosphate groups and between the bases. Causes the DNA to adopt a “twist-like” stance

More Related