Why do we Study DNA?

1. Why do we Study DNA? Disease Better vegetable, fruit, and animals. Crime History of life

2. DNA Karotype

4. Gene: segment of DNA on your chromosomes that determines your traits. • Trait: characteristics about you. It can be a part or a behavior. You inherited your traits from your parents. • Chromosomes: 23 pairs made up of DNA wind around histones (proteins). • What is the human genome?

6. DNA Facts • One chromosome has 50 - 250 • million base pairs. • DNA is found in the mitochondria. • One sequence of DNA is a genome or • gene. • *DNA molecules are incredibly long. If all of the DNA from all of your cells was • stretched out into a single thread, it would extend to the moon and back about one million times!

7. The human genome is contained in 23 pairs of chromosomes. • The DNA within the human genome makes up 60,000 to 100,000 genes.

8. . • Humans get one complete set of genes from each parent. • In April 2003, the National Human Genome Research Institute (NHGRI) celebrates • the completion of the human genome sequence and the 50th anniversary of the description of the DNA double helix. • The nucleus, or control centre, of a cell, is where DNA is located.

10. http://genomics.energy.gov/gallery/chromosomes/gallery-01.htmlhttp://genomics.energy.gov/gallery/chromosomes/gallery-01.html

12. Karotype • A display of metaphase chromosomes of a cell arranged by size and centromere positions. • From these pictures, doctors can study to chromosomes to look for disorders.

13. Genetic material of cells… What is the type of organic molecule? • Madeup of DNA • Called NUCLEIC ACIDS • DNA is made up of repeating monomers called NUCLEOTIDES

14. DNA(Deoxyribonucleic Acid)

15. How do we know that all of our genetic information comes from DNA? • What type of experiment would you design to determine that DNA is the source of all genetic information?

16. Fredick Griffith’s Experiment • Injected mice with two bacteria - one that made them sick and one that didn’t. • He boiled bacteria A and then the mice did not get sick. • He injected both bacteria A(boiled) and bacteria B into mice and they got sick. CONCLUDED - Transformation occurred. Bacteria causing bacteria changed the harmless bacteria. Passed on genes somehow.

17. Griffith’s Experiment with Pneumonia and the accidental discovery of Transformation • Frederick Griffiths was a bacteriologist studying pneumonia • He discovered two types of bacteria: • Smooth colonies • Rough colonies

18. Griffith’s Experiment with Pneumonia and the accidental discovery of Transformation CONCLUSION: The smooth colonies must carry the disease!

19. When heat was applied to the deadly smooth type… And injected into a mouse… The mouse lived! Griffith’s Experiment with Pneumonia and the accidental discovery of Transformation

20. Griffith’s Experiment with Pneumonia and the accidental discovery of Transformation • Griffith injected the heat-killed type and the non-deadly rough type of bacteria. • The bacteria “transformed” itself from the heated non-deadly type to the deadly type.

21. Avery, McCarty, and MacLeodRepeated Griffith’s Experiment Oswald Avery Maclyn McCarty Colin MacLeod

22. Avery, McCarty, and MacLeodRepeated Griffith’s Experiment

23. Avery, McCarty, and MacLeodAdded the non-deadly Rough Type of Bacteria to the Heat-Killed Smooth Type To the Heat-Killed Smooth Type, added enzymes that destroyed… Carbohydrates Lipids Proteins RNA DNA

24. S-Type Carbohydrates Destroyed S-Type Lipids Destroyed S-Type Proteins Destroyed S-Type RNA Destroyed S-Type DNA Destroyed Conclusion: DNA was the transforming factor!

25. The Hershey-Chase Experiment Protein coat Alfred Hershey & Martha Chase worked with a bacteriophage: A virus that invades bacteria. It consists of a DNA core and a protein coat DNA

26. Protein coats of bacteriophages labeled with Sulfur-35 Phage • Hershey and Chase mixed the radioactively-labeled viruses with the bacteria Bacterium Phage The viruses infect the bacterial cells. Bacterium DNA of bacteriophages labeled with Phosphorus-32

27. Hershey - Chase Injected bacteriophages with radioactive isotopes then placed them with bacteria. The virus injected the bacteria with DNA containing radioactive material. Then tested for the radioactive material. COCNLUDED: Viruses passed on their DNA to the bacteria.

28. The Hershey-Chase results reinforced the Avery, McCarty, and MacLeod conclusion: DNA carries the genetic code! However, there were still important details to uncover…

29. A HISTORY OF THE STRUCTURE OF DNA • Discovery of the DNA double helix A. Rosalind Franklin- Used X-ray photo of DNA to discover the shape was a double helix. (1952) B. Watson and Crick- Used Franklin’s work to build the first model of DNA. They figured out the exact structure. (1953)

30. Discovery of DNA Invented X-ray diffraction photography. Photo used to determine the shape of DNA is spiral. Rosalind Franklin -

31. DISCOVERY OF DNA James Watson and Francis Crick used the information from Franklin and other scientists to build a 3-D model of DNA. Won the Nobel Piece Prize in Chemistry in 1961.

32. Watson & Crick proposed… • DNA had specific pairing between the nitrogen bases: • ADENINE – THYMINE • CYTOSINE - GUANINE • DNA was made of 2 long stands of nucleotides arranged in a specific way called the “Complementary Rule”

33. DNA DNA stands for – Deoxyribonucleic acid Functions of DNA: 1. Carries the codes to make proteins. • Carries the genetic material that is passed on from the parents to the offspring.

34. STRUCTURE OF DNA These three parts the basic unit of DNA NUCLEOTIDE(monomer). phosphate Nitrogen base Can be A, T, C or G Sugar (deoxyribose)

35. STRUCTURE OF DNA Side Pieces(The Rope Part) Are alternating units of a 5 carbon sugar and a phosphate group. These go down both sides of the molecule phosphate Sugar (called deoxyribose)

36. STRUCTURE OF DNA Nitrogen Bases (Steps of the ladder) - • Adenine - A • Thymine – T • Cytocine – C • Guanine - G 2. The bases are connected to the sugar only !!!!!

37. Phosphate Group O O=P-O O 5 CH2 O N Nitrogenous base (A, G, C, or T) C1 C4 Sugar (deoxyribose) C3 C2 DNA Nucleotide

38. phophate adenine sugar thymine cytocine guanine

39. How are the nucleotides held together? • Nucleotides are held together by covalent bonds between the sugar of one nucleotide and the phosphate of the next.

40. DNA

41. Amount of DNA • Amount of DNA in a sample can be determined by how much UV light is absorbs. DNA absorbs UV light!!!

42. “Rungs of ladder” Nitrogenous Base (A,T,G or C) “Legs of ladder” Phosphate & Sugar Backbone DNA Double Helix

43. A or G T or C Nitrogenous Bases • PURINES 1. Adenine (A) 2. Guanine (G) • PYRIMIDINES 3. Thymine (T) 4. Cytosine (C)

44. H-bonds G C A T BASE-PAIRINGS 2 Bonds 3 bonds

45. STRUCTURE OF DNA One complete turn of the double helix is 10 base pairs or 10 steps on the ladder

46. DNA is antiparallel The two strand of DNA run opposite of each other. The happens because of the structure of the nitrogen bases. To fit together,they must be upside down.

47. 5 O 3 3 O P P 5 5 C O G 1 3 2 4 4 2 1 3 5 O P P T A 3 5 O O 5 P P 3 DNA Double Helix

48. C T A G Chargaff’s Rule • Adeninemust pair with Thymine • Guanine must pair with Cytosine • Their amounts in a given DNA molecule will be about the same.

49. Chargaff’s Rule • In his experments on several different organisms, Chargaff discovered that the percentage of A and T were equal. The same for C and G. This observation became Chargaff’s rule. This is always the same no matter what organisms.

50. Video of girl burned!! • United streaming