2. DNA

3. Roles of DNA 1. 2.

4. Pop Quiz 1. What was the main goal of Griffith’s experiment? What was the procedure? What were the results? 2. What was the main goal of the experiment performed by Hershey and Chase? What was the procedure? What were the results? 3. How did Watson and Crick use the discoveries of scientists before them to develop the alpha helix model of DNA?

5. Discovery

6. Griffith’s Experiment (1928)

7. Avery (1944)

8. Chargaff (1949)

9. Hershey and Chase

10. Wilkins and Franklin (1952)

11. Nucleotides

12. A Closer look…

13. Watson, Crick, and the Double Helix

14. Nucleotides

15. A Closer look…

16. Base Pairing Rules

17. Human Genome Project

19. DNA Replication http://www.mcb.harvard.edu/losick/images/trombonefinald.swf http://www.pc.maricopa.edu/Biology/rcotter/BIO%20205/LessonBuilders/Chapter%209%20LB/DNAReplication.mpg

21. Protein Synthesis

24. Part I: Transcription

26. Part II: Translation

27. Gene Expression/Regulation in Prokaryotes

28. Gene Expression in Eukaryotes

30. Homeotic Genes

32. Homeotic Genes/Homeobox

34. DNA Structure and Function

35. Watson and Crick An Englishman and an American discovered the structure of DNA in 1954. DNA is to small to see so they had to build a model using x-Rays and chemical information about Nitrogen bases

36. They Had Some Help Roselyn Franklin took this x-ray picture of DNA which lead Watson and Crick to the double helix structure of DNA but they failed to give her credit until much later.

37. Double Helix DNA consists of two strips, made of sugars and phosphates, twisted around each other and connected by nitrogen bases. Looks like a spiral staircase or a twisted ladder.

38. Sugar Backbone The backbone of DNA is made up of Deoxyribose (Sugar) molecules connected to each other using Phosphates

39. Nitrogen Bases DNA contains 4 nitrogen bases that make up the “code” for all living things. A = Adenine T = Thymine G = Guanine C = Cytosine A always bonds to T G always bonds to C

40. Nucleotide The combination of a sugar, phosphate and nitrogen base is called a Nucleotide. These are the building blocks of DNA.

42. Key Words for Protein Synthesis Gene- section of DNA that codes for a specific protein. Messenger RNA (mRNA)- nucleic acid that copies the DNA and takes it to the Ribosome. Ribosome- Organelle that builds proteins using mRNA and tRNA. Transfer RNA (tRNA)- nucleic acid that matches up codon to anticondon and drops off amino acids in the correct order.

43. Key Words Continued Codon- Group of three nitrogen bases found on the mRNA that codes for a specific amino acid. Anticodon- Group of three nitrogen bases found on the tRNA that matches up with the codon and drops off the correct amino acid. Amino Acid- Building blocks of proteins that are placed in the correct order by matching codon to anticodon along the length of a gene.

44. Steps to Protein Synthesis Transcription DNA Opens one Gene One side of the DNA is copied by the mRNA mRNA travels outside the Nucleus to the Ribosome Translation Ribosome attaches to the mRNA. tRNA matches up codon to anticodon and drops off the correct amino acid A chain of amino acids is created which is a protein

46. Translation

47. Protein Synthesis Models https://www.youtube.com/watch?v=NJxobgkP EAo&list=FLEezLUm- pa3vfMmQGp1aPTQ&feature=mh_lolz https://www.youtube.com/watch?v=NJxobgkP EAo&list=FLEezLUm- pa3vfMmQGp1aPTQ&feature=mh_lolz https://www.youtube.com/watch?v=u9dhO0iCLww&list=FLEezLUm-pa3vfMmQGp1aPTQ