1 / 9

11.2 Structure of DNA

11.2 Structure of DNA. Actual structure of DNA was a complete mystery. Big question: How did DNA hold genetic information and what did it look like?. Inheritable genetic information is coded in the molecule called DNA ( Deoxyribonucleic Acid).

feleti
Télécharger la présentation

11.2 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. 11.2 Structure of DNA

  2. Actual structure of DNA was a complete mystery Big question: How did DNA hold genetic information and what did it look like?

  3. Inheritable genetic information is coded in the molecule called DNA (Deoxyribonucleic Acid). DNA is a Polymer - built from monomers called Nucleotides 1. Deoxyribose Sugar - pentagonal ring 2. Phosphate Group - Phosphorus atom surrounded by four Oxygen atoms 3. Nitrogenous Base - a single or double ring of carbon and nitrogen atoms with functional groups

  4. Purines- double ring nitrogenous bases Adenine (A) & Guanine (G) Pyrimidines - single ring nitrogenous bases Thymine (T) & Cytosine (C)

  5. 1950 American Erwin Chargaff Analyzed different organism’s DNA: variation in number and amount of A, T, G, C Quantity of nucleotides in each organism he found A=T and G=C Chargaff’s Rule: Nucleotide number and concentration vary with each species. A=T and G=C within a specie’s DNA

  6. 1951 English Rosalind Franklin Studied molecules using X ray Diffraction Indicated a helix structure

  7. 1953 American James Watson and English Francis Crick Studying the structure of DNA Rosalind wrote to Watson and when he saw the X-Ray evidence he also believed DNA to be a Helix

  8. Complementary Base Pairing Each nitrogenous base must pair (bond) with its complementary base each fitting like a puzzle piece Adenine (A) pairs to Thymine (T) Guanine (G) pairs to Cytosine (C)

  9. Two long chains of nitrogenous bases bond with their base pair and form a ladder structure "Backbone" are the phosphate and deoxyribose "rung" of the ladder isthe Nitrogenous bases

More Related