3. dna


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3. dna

  1. 1. I. Review Biological CompoundsA. Typescategory monomer polymerCarbohydrate glucose starchLipids glycerol, fatty acid fat, oilProtein amino acid proteinNucleic Acid nucleotide DNA, RNA
  2. 2. B. Protein A sequence of amino acids held together by peptide bonds There are 20 different types of amino acids and the different arrangements of bonding determines the protein
  3. 3. B1. Structure1.Primary Structure Sequence of amino acids = chain2. Secondary Structure Folds & bends due to amino acid interactions3. Tertiary Structure 3-D shape (usually functional enzyme)4. Quaternary Structure More than one chain of amino acids
  4. 4. C. Nucleic Acids1.Types Monomer Polymer DNA Nucleotide DNA RNA Nucleotide RNA
  5. 5. 2. Components of nucleotides a. Phosphate Group – symbol O- | H- O- P=O | O-
  6. 6. b. 5 – Carbon Sugar Deoxyribose RiboseC5 C5 O OC4 C1 C4 C1C3 C2 C3 C2HO H HO OH
  7. 7. c. Nitrogen Base DNA RNAPurines Adenine (A) Adenine (A)(2 rings) Guanine (G) Guanine (G)Pyrimidine Thymine (T) Uracil (U)(1 ring) Cytosine (C) Cytosine (C)
  8. 8. 3. Base Pairing A=T A=U C=G C=G
  9. 9. D. Definitions1.DNA – A double-helix molecule made of DNA nucleotides.2. Gene – A segment of the DNA molecule that codes for a specific trait.
  10. 10. 3. Chromosome – A structure made up of either 1 or 2 DNA molecules(each is a double helix)1 DOUBLE HELIX 2 DOUBLE HELIX
  11. 11. II. DNA StructureA.Nucleotides Monomer (4 different types) Bacteria has millions Plants/animals has billions
  12. 12. purine (A), (G) = 2 rings5 N - BASE 4 1 pyrimidine (T)(U)(C) 3 2 = 1 ring
  13. 13. B. Double Helix Polymer1.BackboneThe of one nucleotide (5’) binds withdeoxyribose sugar of another nucleotide(3’).
  14. 14. Covalent bondbetween the ofone nucleotide and3rd carbon ofanother nucleotide.
  15. 15. 2. N-Bases – N base of one nucleotide H bondsto another N base on a separate nucleotide DOUBLE HELIX
  16. 16. Nucleotides N bases paired 2 nm
  17. 17. III. DNA ReplicationCopy the DNA strand (Genetic info) so thatwhen a cell divides (mitosis, meiosis) theyget an exact copy.1. SEMICONSERVATIVEREPLICATION
  18. 18. A. General 3’ 5’ 3’ 5’ 3’ 5’ A T AT AT T A TA TA GC GC GC CG CG CG T A TA TA 5’ 3’ 5’ 3’ 5’ 3’Parental DNA Enzyme reads template 3’ to 5’Double Helix synthesizes new DNA 5’ to 3’
  19. 19. 3’ 5’ 5’ 3’STEP 1 DNA Helicase separates helix by breaking the hydrogen bondsDNA Helicase between the N-bases. replication fork 3’ 5’ 5’ 3’
  20. 20. STEP 2 DNA Polymerase 1. 2 Enzymes bond = 1 to each strand 2. Each enzyme reads the original 3’ to 5’ 3. Each enzyme makes new DNA 5’ to 3’ 4. Pairs free DNA nucleotides with parent strand 5. Bonds P to sugar to form backbone of new strand
  21. 21. 5’ 3’ 5’ 3’ 5’ 3’1.As drawn, upper DNA Polymerase synthesizesnew strand as it follows helicase.2.As drawn, lower DNA Polymerase detaches ascome to unwound DNA helix
  22. 22. 5’ 3’ 5’ 3’ 5’ 5’ 3’Lower DNA Polymerase synthesizefragments and the DNA Polymerasedetach off fragments.
  23. 23. 3’ 5’ 5’ 3’ 3’ 5’ 5’ 3’ STEP 3 DNA Ligase - Joins thebackbone of the strands
  24. 24. Centromere – specific sequence of DNA that joinstwo DNA molecules together.DNA Polymerase proofreads as goes along (only 1mistake/10, 000 pairs but enzymes find and repairthe mistakes).
  25. 25. END RESULT3’ 5’5’ 3’3’ 5’5’ 3’
  26. 26. I. Central DogmaOne gene one protein (really = polypeptide)General: 1. A functional protein may be > 1 chain 2. Not all proteins are enzymes
  27. 27. 3. 1 gene = 100’s-1000’s of nucleotides4. 1000’s genes per chromosome5. Start Stop on mRNA AUG UAG, UAA, UGA
  28. 28. A. Nucleus 3’ 5’DNA T A C C T A C G G’ 5’ 3’ A T G G A T G C CTRANSCRIPTION copy information from DNA gene into mRNA A U G G A U G C CmRNA 5’ 3’
  29. 29. B. Cytoplasm – the mRNA leaves the nucleusby pores & goes to ribosome in the cytoplasmrRNA –makes up part of the ribosome TRANSLATIONtRNA -carries specificamino acids Amino Acid
  30. 30. Converts the information frommRNA into a proteinprimary structure of a proteinsecondary structure of a proteintertiary structure of a protein
  31. 31. II. Protein SynthesisA. DNA vs. RNA double strand single strand thymine uracil deoxyribose ribose
  32. 32. B. RNA types1.mRNA (messenger RNA)Copy (where U replaces T) of DNA templategene (carries DNA code to the ribosme).Enzyme reads the DNA 3’ to 5’ but lays thenew nucleotides down 5’ to 3’ = makesmRNA 5’ to 3’
  33. 33. mRNA (messenger RNA) start stop5’ A U G G A U G C C U A G 3’ CODON (corresponds to one amino acid)Start codon Stop codon AUG UAG UGA UAA
  34. 34. 2. rRNA = Ribosomal RNAMake ribosomes by combining twosubunits (small and large)Where protein synthesis occurs.
  35. 35. Ribosome structure (two subunits) small subunit large subunit 1st binding site 2nd binding site catalytic site
  36. 36. 3. tRNA = Transfer RNABrings amino acids to mRNA/rRNAAnticodon = three consecutive nucleotides on tRNA and pair to the codon on mRNA Codon = AUG Anticodon = UAC Amino Acid = Met = methionine
  37. 37. Structure anticodon UAC Amino Acid
  38. 38. TRANSCRIPTION1. Where Occurs nucleus2. General DNA mRNA Only one side of DNA Helix is copied into mRNA (not always the same side for different genes).
  39. 39. 3. Parts of TranscriptionINITIATIONa. RNA Polymerase binds to a promotor (TATA*****), which tells the enzyme that the gene starts on the complimentary strand of the DNA Helix.
  40. 40. CONTINUE INITIATIONb. RNA Polymerase reads the template 3’ to 5’ but bonds new nucleotides for mRNA 5’ to 3’
  41. 41. PROMOTOR5’ 3’ T A T A A T G C A A C T A T A A3’ A T A T T A C G T T G A T A T T 5’ RNA Polymerase (enzyme)
  42. 42. ELONGATIONa. RNA Polymerase unwinds DNA Helixb. RNA Polymerase moves along the DNA Helix and reads the template 3’ to 5’
  43. 43. c. RNA Polymerase adds (bonds together) free RNA nucleotides 5’ to 3’d. Continues until enzyme reaches stop on DNA
  44. 44. 5’ 3’ T A T A A T G C A A C T A T A A 3’ C A A A T A T T AC G T T G A T A T T3’ 5’ G U 5’ A The RNA Polymerase (blue) is reading the DNA gene (bottom black) from 3’ to 5’ but adding new nucleotides (RNA) from 5’ to 3’. As it does this it is producing the mRNA (RED) 5’ to 3’.
  45. 45. U A A A U C A A C G U AThe RNA Polymerase continues to add RNAnucleotides until it reaches a stop.
  46. 46. 5. Terminationa. Once the RNA Polymerase reaches this point it detaches from the DNA (which reforms the double helix). What is formed is called a transcription unit.
  47. 47. b. RNA SPLICING1.Need to remove introns2.Need to bond together exons3.Need to add cap and tail4.Then have mRNA
  48. 48. DNAmRNA5’ GPPP A U G C A A C U A U A AAAAAAA3’
  49. 49. TRANSLATIONWhere: CytoplasmGeneral: mRNA moves into the cytoplasm. Ribosomes “read” the mRNA. Produce a protein.
  50. 50. 1. INITIATIONUse: tRNA-aa complex Ribsomes mRNA
  51. 51. NIT SMALL SUBU 5’ 3’ A U G C A A C U A U A A U A C mRNAtRNA LARGE SUBUNIT AA1 1ST tRNA enters the site in the large subunit of the ribosome. Bonds to the mRNA with the small subunit.
  52. 52. 5’ 3’ A U G C A A C U A U A A U A C G U U AA1 AA22nd tRNA bonds to the second site in the ribosome.
  53. 53. 5’ 3’ A U G C A A C U A U A A U A C G U U AA1 AA2In the catalytic site AA1 is bonded to AA2.
  54. 54. 5’ 3’ A U G C A A C U A U A A G U UU A C AA1 AA2 Ribosome moves toward the 3’ end of the mRNA. Causes the 1st tRNA to leave and the 2nd site to be open.
  55. 55. 5’ 3’ A U G C A A C U A U A A G U U G A UU A C AA1 AA2 AA3 3rd tRNA enters the open site on Ribosome.
  56. 56. 5’ 3’ A U G C A A C U A U A A G U U G A UU A C AA1 AA2 AA3 The AA1-AA2 bond to AA3.
  57. 57. 5’ 3’ A U G C A A C U A U A A G U U G A UU A C AA1 AA2 AA3Ribosome moves down mRNAtoward the 3’ end.
  58. 58. 5’ 3’ A U G C A A C U A U A AG U U G A U U A C AA1 AA2 AA3Causes 3rd tRNA to move in 1st site and 2nd tRNA leave ribosome sites.Reaches stop codon on the mRNA.
  59. 59. 5’ 3’ A U G C A A C U A U A AG U U G A U U A C AA1 AA2 AA3All detach.