chapter 12.1 molecular genetics
TRANSCRIPT
![Page 1: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/1.jpg)
Chapter 12 – Molecular Genetics
![Page 2: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/2.jpg)
12.1 DNA: The Genetic Material (Pgs. 326-332)
![Page 3: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/3.jpg)
Frederick Griffith (1928)
Studied 2 strains of the bacteria Streptococcus pneumoniae
Found that one strain could be transformed into the other form
![Page 4: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/4.jpg)
Frederick Griffith
Rough Smooth
![Page 5: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/5.jpg)
Oswald Avery (1944)Took Griffith’s work and discovered
that DNA was the “transforming molecule”
![Page 6: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/6.jpg)
Hershey & Chase (1952)
Provided evidence that DNA was the “transforming factor”
Used bacteriophage (virus that attacks bacteria)
Used radioactive labelingRead pp. 327-328
![Page 7: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/7.jpg)
Bacteriophage
Made of DNA and protein
Inject DNA into host cell
![Page 8: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/8.jpg)
Hershey and Chase
![Page 9: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/9.jpg)
DNA Structure
DNA is a nucleic acid that stores and transmits genetic information.
Polymer made up of nucleotides5-carbon sugar (deoxyribose),
phosphate group,
nitrogen base
![Page 10: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/10.jpg)
DNA Structure
P.A. Levine determined basic structure of nucleotides
![Page 11: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/11.jpg)
Base Groupings
Purines (Double ringed)
1. Adenine (A)
2. Guanine (G)
Pyrimidines (Single ringed)
1. Cytosine (C)
2. Thymine (T)
![Page 12: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/12.jpg)
Backbone of DNA chain formed by sugar and phosphate groups of nucleotides
sugar
phosphate
![Page 13: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/13.jpg)
![Page 14: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/14.jpg)
DNA Structure
Nucleotides bond to form 2 long chains (weak hydrogen bonds) resulting in a ladder like structure called a double helix
DNA found in nucleus
![Page 15: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/15.jpg)
![Page 16: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/16.jpg)
Erwin Chargaff
Discovered that base pairing is the force that holds the two strands of the DNA double-helix together
Chargaff’s Rule C=G and A=T
![Page 17: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/17.jpg)
Rosalind Franklin & Maurice Wilkins
Made x-ray diffraction photographs to study DNA structure
Photo 51
![Page 18: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/18.jpg)
James Watson & Francis Crick
Credited with discovering double helix model of DNA (see figure 12.8, p. 331)
C-G pair by 3 hydrogen bondsA-T pair by 2 hydrogen bondsHypothesized a method of replication
![Page 19: Chapter 12.1 molecular genetics](https://reader037.vdocuments.net/reader037/viewer/2022100220/55501b41b4c905af648b4f3d/html5/thumbnails/19.jpg)
Watson and Crick