DNA, Replication, Protein Synthesis

1. DNA, Replication, Protein Synthesis 2013

2. Goals for Today • Know ALL of Genetics • Be able to name the scientists that helped build our knowledge of DNA and be able to describe their contributions

3. Test Corrections Assignment • REWRITE each question completely. • Write out the correct answer (do NOT just put the letter of the correct answer!) • When finished place Study guides, Qods, & Notes in Folders.

4. Introduction to DNA

5. Goals for Today • Be able to name the scientists that helped build our knowledge of DNA and be able to describe their contributions • Be able to discuss how scientific understanding is built • Be able to list or understand the contributions of less known scientists • Be name the 3 basic components of DNA

6. Question of the Day • What is DNA? Write your thoughts down, and what you know about it, you don’t have to be sure you are correct!

7. DNA is shaped like a double helix (a twisted ladder) This shape was discovered by two scientists: James Watson & Francis Crick

8. Scientific Knowledge • Scientific knowledge and discovery is always built on what we already know, past discovery & knowledge • Were Watson & Crick the only ones responsible for discovering the structure of the DNA molecule?

9. Who is Rosalind Franklin?

10. Griffith’s Experiments Griffith discovered that harmless bacteria could turn virulent when mixed with bacteria that cause disease. A bacteria that is virulent is able to cause disease. Griffith had discovered what is now called transformation, a change in genotype caused when cells take up foreign genetic material.

12. MOUSE LIVES!!!! • When virulent bacteria are heat-killed and injected into a mouse…….. • The Mouse Lives! • This told Griffith it was not the PROTEIN capsule on the bacteria that killed the mice.

13. Mouse Dies  • When virulent bacteria are heat-killed and COMBINED with injected into a mouse……..with live non-virulent bacteria. • Mouse Dies • Griffith discovered that the non-virulent bacteria had acquired genes from the virulent bacteria. • This process is now known as transformation

14. Avery’s Experiments • In 1943, a series of experiments showed that the activity of the material responsible fortransformationis not affected by protein-destroying enzymes. • The activity is stopped, however, by a DNA-destroying enzyme. • Thus, almost 100 years after Mendel’s experiments, Oswald Avery and his co-workers demonstrated thatDNAis the material responsible for transformation NOT protein.

15. DNA Nucleotide – a nucleotide is the three component parts together Phosphate Group N Nitrogenous base (A, G, C, or T) Sugar (deoxyribose)

16. Goals for Today • Be able to name the scientists that helped build our knowledge of DNA and be able to describe their contributions • Be able to discuss how scientific understanding is built • Be able to list or understand the contributions of less known scientists • Be name the 3 basic components of DNA

17. Question of the Day • What are the contributions of these two scientists: • Griffith: - • Avery -

18. DNA’s Role Revealed In 1952, Alfred Hershey and Martha Chase used thebacteriophageT2 to prove thatDNAcarried genetic material. Abacteriophage,also referred to as phage, is a virus that infects bacteria. Whenphagesinfect bacterial cells, thephagesare able to produce more viruses,which are released when the bacterial cells rupture.

19. Life Cycle of a virus (bacteriophage)

20. Hershey & Chase use viruses to prove DNA is the genetic material

21. Who is Rosalind Franklin?

22. Erwin Chargaff • Chargaff’s research determined that in DNA there were always equal parts • Adenine = Thymine As well as equal parts • Cytosine = Guanine

23. Goals for Today • Be able to name the scientists that helped build our knowledge of DNA and be able to describe their contributions • Be name the 3 basic components of DNA • Be able to list and describe the nitrogen bases and how they pair

24. Question of the Day What are the contributions of these scientists: • Chargaff: • Hershey & Chase:

25. Question of the Day continued Chargaff - Determined that in DNA there are always equal parts Adenine-Thymine & equal parts Cytosine-Guanine Hershey & Chase-Used bacteria & Viruses to prove that DNA was the genetic material

26. DNA…. what is good for? • DNA has 2 major functions in our body: • Make more DNA • Make Protein

27. The Structure of DNA • DNA – Deoxyribonucleic Acid • A double helix • Made of 3 basic components: • Sugar • Phosphate Group • Nitrogen bases

28. The backbone of DNA • The Sugar (deoxyribose) & phosphate group form the “backbone” of DNA or the sides of the ladder.

29. DNA Nucleotide – a nucleotide is the three component parts togetherThe Nitrogen Base is the Variable Piece of the Nucleotide N Phosphate Group Nitrogenous base (A, G, C, or T) Sugar (deoxyribose)

30. Nitrogenous Bases Purines • A –Adenine • G – Guanine Pyrimidines • T – Thymine • C - Cytosine

31. Rosalind Franklin It was Franklin’s photograph that ultimately allowed Watson & Crick to get the correct base pairing, because they now new exactly how wide the helix was (The width between the sides of the double helix). • Additionally, it was Franklin who suggested that the bases would go on the inside of the helix & not the outside as Watson & Crick originally thought

33. Nitrogenous Base Pairing Nitrogen bases form the rungs of the “ladder” by forming Hydrogen bonds What Watson & Crick had to figure out was how the bases paired up

34. Nitrogen Base Pairing • There were 3 scientists, other then Rosalind Franklin, whose research & help contributed to Watson & Crick coming up with the correct pairing of the nitrogen bases • Adenine - Thymine • Cytosine - Guanine

35. 2 Hydrogen bonds between Adenine & Thymine3 Hydrogen bonds between Cytosine & Guanine

36. DNA Nucleotide – a nucleotide is the three component parts together Phosphate Group N Nitrogenous base (A, G, C, or T) Sugar (deoxyribose)

37. Goals for Today • Be able to describe the process and enzymes involved in DNA replication. • Be able to list and describe the nitrogen bases and how they pair • Be name the 3 basic components of DNA

38. Question of the Day What are the contributions of these scientists: • Rosalind Franklin: • Watson & Crick:

39. Question of the Day continued Rosalind Franklin- Her research provided the basis for the first accurate model of DNA Watson & Crick- First to accurately describe and model the chemical structure of DNA

41. Base Pairing Practice!

42. DNA…. what is good for? • DNA has 2 major functions in our body: • Make more DNA • Make Protein

43. Making More DNA… • DNA replication is the process we use to make more copies of DNA • When would we need to make more DNA?

44. Making More DNA… • DNA is copied in the “S” phase of interphase to prepare for cell division. • DNA replication occurs so new daughter cells will have the same information and the same number of chromosomes as the parent cell.

45. Enzyme Review *What two things can enzymes do?

46. What has to break for the DNA strand to come apart?

47. DNA Replication DNA replication occurs in 3 basic steps: • The enzyme DNA helicaseopens the double helix by breaking the hydrogen bonds that link the complementary nitrogen bases between the two strands. • Complementary bases -

48. DNA Replication

49. DNA Replication • The Enzyme DNA polymerasemove along each of the DNA strands. DNA polymerase adds nucleotides to the exposed nitrogen bases, according to the base-pairing rules. • Two DNA molecules form that are identical to the original DNA molecule. *What do both of these enzymes end in?

50. DNA Replication DNA Replication is known as “Semiconservative process” Semi = Conserve =