DNA the GENE

1. DNA the GENE

5. Discovery of DNA Frederick Griffith Was studying Streptococcus Pneumonia Smooth vs. Rough Strains Smooth had a mucous coat and were pathogenic (caused pneumonia) Rough were non-pathogenic Conducted an experiment with mice Found out that the Rough bacteria became transgenic with the Smooth and killed the mouse

7. Discovery of DNA Avery, McCarty and MacLeod What was the genetic material in Griffith�s experiment? Purified the heat�killed S-bacteria Into DNA, RNA, and Protein Mixed each with the R cells to see which one transformed

8. 3. Meselson-Stahl demonstrate the Semiconservative Replication of DNA using radioactive nitrogen

10. Discovery of DNA Hershey-Chase Experiment Studied viruses that infect bacterial cells called Bacteriophages Viruses use Bacteria to multiply Protein or DNA responsible for multiplying within the bacteria Tagged the Protein with radioactive S Why? Tagged the DNA with radioactive P Why? Checked the Virus Progeny for Radioactive Elements

12. 1. Griffith Experiment demonstrates the Transformation of bacteria : DNA is later found to be the transforming principle

13. 2. Hershey-Chase demonstrate DNA is hereditary material not proteins by using radioactive isotopes

14. 3. Meselson-Stahl demonstrate the Semiconservative Replication of DNA using radioactive nitrogen

15. From Chromosomes to Genes

16. From Chromosomes to Genes

17. The Structure of DNA:a double helix? Chargaff�s Nucleic Acid Ratios Measured the base compositions of several species Percentage of each base present Human DNA A = 30% and T = 29% G = 20% and C = 19%

18. Rosalind Franklin and Maurice Wilkins use X-Ray diffraction to view structure Watson and Crick propose a double helix using their X-Ray pictures The Structure of DNA:a double helix?

19. DNA Helix

20. DNA Structure Watson and Crick propose a double helix and construct a model of DNA based on an accumulation of various researchers.

21. James and Francis

22. DNA Basic Composition DNA is made up of nucleotides Nucleotides are made of ����...Deoxyribose sugar �����Phosphate �����Base bases are guanine,cytosine, thymine and adenine

23. DNA: The Deoxyribose Sugar

24. DNA: The Phosphate

25. DNA: The Nitrogenous Bases Purines Adenine and Guanine Double Ring Structure Pyrimidines Thymine and Cytosine Single Ring Structure

26. DNA CANDY LABDNA CANDY LAB

28. Why do they pair up? Double helix had a uniform diameter Purine + Purine = too wide Pyrimidine + Pyrimidine = too narrow Purine + Pyrimidine = fits the x-ray data

29. DNA Double Helix

30. How does it know to pair up? ADENINE ALWAYS PAIRS WITH THYMINE Two hydrogen bonds GUANINE ALWAYS PAIRS WITH CYTOSINE Three hydrogen bonds

31. Purines Adenine Guanine All double ring structures

32. DNA BASE PAIRS

33. Pyrimidines Cytosine Thymine single ring

34. DNA Structure

35. Single stranded

37. DNA STRUCTURE

38. One last look

39. DNA Replication

41. Why must DNA Replicate? Species Survival DNA must replicate BEFORE cell division Synthesis during Interphase All genes must be present in the daughter cells

42. How does DNA Replicate? Hydrogen bonds break, forming bubbles Enzymes unwind and unzip Free nucleotides in the nucleus start process of complementary base pairing Nucleotides are fused together by DNA Polymerase only 5� to 3� Results in two identical double helixes

43. How does DNA Replicate?

44. How does DNA Replicate?

45. DNA and RNA functions Replication, Transcription, and Translation

46. replication

47. Replication Steps Leading Strand DNA helicase uncoils and unzips exposing the DNA . Single stranded binding proteins hold them apart. Topoisomerase helps relieve strain on open strand Primase adds RNA primer DNA polymerase III adds free nucleotides bases pair A-T and G-C as new strand is added in a 5� to 3� direction

48. Lagging strand is done in segments as each primer is added only after a coding segment is exposed. That means the end of it can not be replicated. Last primer only has a 5� end . Telomeres�ends of chromosomes have repeating nonsense sequences. TTAGGG As cells age the ends shorten until it can no longer replicate the DNA

50. Proteins are critical Helicase-unwinds parental DNA Single-strand binding protein-stabilize DNA strands Primase-makes single RNA primers at 5� end of the leading strand DNA polymerases I. Removes primer and replaces with DNA III. Continuously synthesizes the leading strand and replaces it with DNA adding to 3� end only elongates each Okazaki fragment

51. Telomerase � replaces DNA nucleotides where RNA primer was located on the leading strand.

52. Lagging Strand Lagging strands begin with addition of Primase and then RNA primer DNA polymerase I adds nucleotides in segments known as Okazaki Fragments Ligase glues fragments together of lagging strand

53. Proofreading and Repairing DNA Mismatch repair �enzymes remove incorrectly paired nucleotides Nuclease enzymes cut out damage mutagens and carcinogens can cause these mismatches( uv light , x �rays, reactive chemicals) Nucleotide excision repair

54. replication3

55. function of DNA

56. RNA Nucleotides Made of the following: ���Ribose sugar ���Phosphate one of four bases ( uracil replaces thymine)

57. Types of RNA M RNA- messenger RNA carries the DNA instructions(gene) out of nucleus to ribosome tRNA-transfer RNA carries amino acids to their appropriate location during protein synthesis ( gene expression ) r RNA - ribosomal RNA makes up much of the ribosome and is essential to translation

58. Transcription in 3 steps 1. Initiation RNA polymerase binds to promoter region DNA unwinds and 2. Elongation polymerase initiates RNA synthesis one nucleiotide at a time 5�-3� 3.Termination- transcript released at terminator sequence

59. Eukaryotic Transcription Steps RNA polymerase II-binds to promoter regions mediated by proteins called transcription factors keys on upstreamTATA box with help of protein transcription factors-transcription initiation complex DNA uncoils and exposes template-RNA nucleotides base pair with DNA template A-U, G-C via RNA polymerase Elongation-nucleotides added to 3� end of transcribed single strand The sequence called polyadenylationAAUAAA-signals proteins to cut mRNA free

60. Prokaryotic Transcription RNA Polymerase binds to promoter region Signal ends at Terminator sequence RNA polymerase detaches several nucleotides down stream

61. Promoter Regions direct Transcription

62. Transcription

64. Termination AAATAAA- release mRNA

65. DNA Processing

66. Processing Genetic Material After transcription mRNA is PROCESSED INTRONS ARE DELETED A CAP 5� end is capped with a modified guanine (G-p-p-p) AND TAIL IS ADDED 50-250 nucleotides added to 3� end( poly A tail AAA-AAA) Introns are non coding units Exons are expressed regions of RNA

67. RNA splicing cut and paste Small sequences at the end of each intron contain a signal for splicing. snRNP�s � small nuclear ribonucleoproteins join together to form a SPLICEOSOME ---these release the introns and join the exons alternative RNA splicing Ribozymes- rna acts as an enzyme

68. Translation Steps Messenger RNA is at the ribosome and the tRNA nucleotides will base pair A-U, G-C The tRNA has the amino acid attached to it and when it finds the right codon the RNA anticodon places the amino acids in their proper sequence for protein synthesis The bond that forms between two amino caids is called a peptide bond. ���Base ( Uracil replaces Thymine)

70. Aminoacyl-tRNA syntase matches each amino acid to the correct tRNA

71. Steps in Translation 1. Initiation 2. Elongation-elongation factors enable addition of tRNAs to A site. codon recognition peptide bonds form

72. 3. translocation -tRNA move from A site to P site 4. Termination-UAA, UAG UGA stop the process

73. Polyribosomes- clusters of ribosomes translating the same mRNA

76. Gene Expression Various cells express different genes Organization of chromatin controls expression Regulation of expressed genes occurs at each step Control of transcription is most important regulatory mechanism ( binding factors and enhancers) some binding factors are sensitive to hormones

77. Prokaryotic + gene control or feedback---- a metabolite or substrate causes gene to be expressed by acting as a transcription factor. - neg. feedback the metabolite or substrate causes the removal of a blocking regulator

80. Key to lac operon inducible enzymeNegative Feedback a. regulatory gene b. promoter c. operator d. structural genes e. operon f. RNA polymerase g. active repressor h. inducer metabolite lactose i. mRNA for variousenzymes to degrade lactose

83. Eukaryotic Gene Expression Heterochromatin to euchromatin-uncoiling and loss of DNA compaction Attachment of acetyl groups to histone proteins Metylation of DNA makes it unable to be expressed

84. 2. Transcriptional control Promoter region where a transcription initiator complex( including RNA polymerase II ) must bind. General Transcription factors bind to RNA polymerase, this may be facilitated by binding specific transcription factors Proximal Control elements Distal Control elements-enhancers�bend in DNA

85. 3. Post-transcriptional Control Processing- alternative exon splicing can produce a variety of genes mRNA degradation-nuclease hydrolysis Micro RNA complimentary binds and blocks m RNA transcript Binding proteins can attach to mRNA and prevent translation

86. Protein Processing Polypeptides can be cleaved or groups attached, and quaternary structure will result in additional folding Proteins can be degraded Selective Transport

87. Transposons Stretches of DNA that can move from one location to another ( Jumping genes)

89. DNA TECHNOLOGIES SEQUENCING-determine order of bases PCR (polymerase chain reaction)-makes repeated copies of desired DNA RFLPS(restriction fragment length polymorphs) -unique gene fragments used as a fingerprint Gel Electrophoresis- separate DNA by size on a gel bed Probes- Radioactive tags label DNA

90. PCR-polymerase chain reaction Makes several copies of DNA adjust temperature and enzyme addition of nucleotides with DNA polymerase

95. Prepare single strand complimentary DNA

96. Mix hybrid (Known fragment as Hybrid )

97. Hybrid 3

98. Blot on Nylon Film

99. Use probe to identify position of gene on a chromosome

101. Reverse Transcriptase Viral enzyme transcribes DNA from RNA if you know the protein you can dtermine the mRNA which makes the protein revers the transcription process to make DNA

103. Sequencing Methods Chain termination- Sanger Method Restriction enzymes specific Restriction fragments vary in size gel electrophoresis resolves the fragments

104. Chain Termination Method-uses dedeoxynucleotides that terminate the synthesis of DNA strands at specific bases

105. Electrophoresis

106. Restriction Analysis

107. RFLP restriction fragment length polymorph

108. RFLPS Restriction fragments are created by cutting DNA with enzymes that cut at specific locations and create fragments of various size. These fragments can then be amplified and separated by gel electrophoresis

109. DNA Fingerprints

111. VNTRvariable number tandem repeats

112. Restriction Analysis

117. Other Technologies Recombinant DNA - gene splicing Transgenic organism- an organism that contains another organism�s DNA

118. Recombinant DNA Plasmid DNA Ligase enzyme Bacterial Cell Restriction Enzyme Bacterial cell wall Host cell Sticky ends Vector DNA fragment desired gene to be cloned

125. Transgenic Organism

127. Genetic Research has created a wealth of information