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DNA and its Processes

DNA and its Processes. Chapter 12 Material on Midterm. Section 12-1: DNA. There are several scientists that have contributed to our understanding of DNA Griffith Avery Hershey-Chase Chargaff Franklin Watson-Crick. Griffith. Section 12-1: DNA. Answer these questions

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DNA and its Processes

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  1. DNA and its Processes • Chapter 12 • Material on Midterm

  2. Section 12-1: DNA • There are several scientists that have contributed to our understanding of DNA • Griffith • Avery • Hershey-Chase • Chargaff • Franklin • Watson-Crick

  3. Griffith

  4. Section 12-1: DNA • Answer these questions • What are the two types of strains? • Seeing what happens to mice injected with virulent strains, what do you think “virulent” means?

  5. Section 12-1: DNA • Frederick Griffith • Responsible for _____________________ • Process in which one strain of bacteria is changed by gene(s) from another strain • Worked with mice and pneumonia • Mice that were injected with rough or heat-killed smooth strain __________ • Mice that had the smooth strain _______ • Mice that had the heat-killed smooth but living rough _____. • Why?

  6. Avery

  7. Section 12-1: DNA • Answer these questions • What does the “S” strain do to mice again? • What enzyme destroys proteins? • What enzyme destroys RNA? • What enzyme destroys DNA? • Which enzyme prevented the smooth strain to grow?

  8. Section 12-1: DNA • Oswald Avery • Responsible for determining that the molecule important in transformation was _______________________ • Took heat-killed bacteria and made extract • Enzymes for lipids, proteins, and carbohydrates—________ • Still transformation of smooth strain • Enzymes for nucleic acid—_____________ • Smooth strain not transformed

  9. Hershey & Chase

  10. Section 12-1: DNA • Answer these questions • Why did they use radioactive sulfur for identifying protein? (Think about the elements in protein!) • Why did they use radioactive phosphorus for identifying DNA? (Think about the elements in DNA!) • Which is more dense—DNA or protein? • What remained in the bacteria—DNA or protein?

  11. Section 12-1: DNA • Alfred Hershey and Martha Chase • Determined that the ___________________ is made out of DNA, not protein • Used radioactive labels • _________-35 for protein—CHOSN for protein • ______________-32 for nucleic acid—CHOPN • Genetic material glowed with P-32…_____

  12. Section 12-1: DNA • Chargaff • Looked at numerous organisms • Compared concentrations of nitrogenous bases (bases) • What do you notice? ___________________________ Chargaff had no idea WHY this was happening!

  13. Section 12-1: DNA • Rosalind Franklin • Used X-ray diffraction to study image of DNA • __________ shape • Twisted strands • ___ strands • Bases near ________

  14. Section 12-1: DNA • What words do you not recognize in the paper? Make a list. • How does the length of the paper compare to a normal scientific article (around 5 pages)? • Why don’t they like Pauling’s and Corey’s model (2 reasons)? • How many helical chains do they propose? • How many base pairs (residues) are in the chain before it repeats? • Where are the phosphates located? • What type of bond joins the bases? • What base pairing rules do they suggest? • What is the sugar?

  15. Section 12-1: DNA • Built 3-D models of DNA • Used work of everyone before them • Model: double helix • Twisted ladder • H-bonds between nitrogenous bases • Base pairing: A with T, G with C • EXPLAINS CHARGAFF

  16. SUM IT UP!

  17. 12-1: DNA • Components & Structure of DNA • What are the monomers and polymers of nucleic acid? ____________ ___________ • __________-stranded • Each nucleotide is made up of three parts • ___________________ • _____________________ • 4 types • ______________________ • Deoxyribose

  18. 12-1: DNA • 4 different nitrogenous bases • Guanine (__) • Adenine (__) • Cytosine (__) • Thymine (__) __ pairs up with __, and __ pairs up with __

  19. 12-1: DNA The Sugar and the Phosphate group are the ____________ of DNA (covalent bonds) • Role of hydrogen bonds • SUMMARY:

  20. Section 12-1: DNA • Purines • ___ rings • Nucleotide __denine • Nucleotide __uanine • Pyridimes • ___ ring • Nucleotide __hymine • Nucleotide __ytosine Two styles of nucleotides based on size Ones with “y” are pyrimidines Longer word; less rings

  21. SUMITUP

  22. 12-2: Chromosomes and DNA Replication • Think back to mitosis…What happens in the “S” phase of interphase?

  23. 12-2: Chromosomes and DNA Replication • When DNA goes through mitosis, it __________ for easy sorting and separation • When its thin, it’s chromatin • Wrapped around histone proteins like beads on a string • Coils up • Coils coil up • A chromosome is the _____________ form of DNA

  24. 12-2: Chromosomes and DNA Replication • The path to condensation

  25. 12-2: Chromosomes and DNA Replication • Your turn!

  26. DNA condensation • DNA replication • Goal: two ___________ strands of DNA • General steps: • ________ double-strands • _____ new base pairs • ______________

  27. 12-2: Chromosomes and DNA Replication If I were an enzyme… • DNA Replication • DNA helicase comes in and __________ the double helix • _______ primers are added • DNA ________________ ‘lands’ on primers and adds new base pairs • Two identical daughter strands result

  28. 12-2: Chromosomes and DNA Replication • Parent strand • DNA helicase separates • DNA Polymerase adds • DNA ligase cleans up

  29. 12-2: Chromosomes and DNA Replication • It the parent strand is AATCCG, what will the result be? TTAGGC • If we are looking at ONE HALF of a DNA strand for DNA polymerase to add bases to, what would the other half be? GTCAGTTCCATCCTAG

  30. 12-2: Chromosomes and DNA Replication • SUM IT UP!

  31. 12-3: RNA and Protein Synthesis • Components & Structure of RNA • What are the monomers and polymers of nucleic acid? ____________ ___________ • _________-stranded • Each nucleotide is made up of three parts • _____________ • __________________ • 4 types • 5-carbon sugar • ___________

  32. 12-3: RNA and Protein Synthesis • 4 different nitrogenous bases • Guanine (G) • Adenine (A) • Cytosine (C) • Uracil (___) A pairs up with U, and G pairs up with C

  33. 12-3: RNA and Protein Synthesis

  34. 12-3: RNA and Protein Synthesis

  35. 12-3: RNA and Protein Synthesis • Sum it up!

  36. 12-3: RNA and Protein Synthesis • Messenger RNA • ___RNA • ____________ copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cell Involved in protein synthesis

  37. 12-3: RNA and Protein Synthesis • Ribosomal RNA • ____RNA • RNA that makes up a major part of the ___________ • Site of protein synthesis ALSO involved in protein synthesis

  38. 12-3: RNA and Protein Synthesis • Transfer RNA • ___RNA • _____________ amino acid to ribosome during protein synthesis And STILL involved in protein synthesis

  39. SUM IT UP

  40. 12-3: RNA and Protein Synthesis • Transcription • Goal: make a strand of __________ that “pairs up” with a template strand of DNA • _________________ strand • Steps • _______ double helix • _____ in RNA bases • Break away and ______________

  41. 12-3: RNA and Protein Synthesis • Transcription • ____________________ does the job of DNA helicase and DNA polymerase combined • _________ and adds ________, but only to the TEMPLATE strand (coding strand)

  42. 12-3: RNA and Protein Synthesis • It the parent strand is AATCCG, what will the result be if the TOP TTAGGCstrand istranscribed? • If we are looking at ONE HALF of a DNA strand for RNA polymerase to add bases to, what would the other half be? GTCAGTTCCATCCTAG

  43. 12-3: RNA and Protein Synthesis • SUM IT UP • Write TWO LINES about the similarities between replication and transcription • Write TWO LINES about the differences between replication and transcription

  44. 12-3: RNA and Protein Synthesis • Genetic Code • What do you see?

  45. 12-3: RNA and Protein Synthesis • The “code” in mRNA specifies the type and order of amino acids • REWIND: amino acids are the monomers of _________ • The goal of the code is to help ________________!

  46. 12-3: RNA and Protein Synthesis • Try the code! • AUG • AUU • UAC • CAC • GGG • UAC • UUU • UAG • Most important 4 • UAA, UAG, UGA • _________ • AUG • “________” • Also MET

  47. 12-3: RNA and Protein Synthesis • Translation • Goal: Make a polypeptide chain (_________) from the information stored in mRNA • Involves all three types of RNA! • Steps • Have mRNA go in ribosome • Ribosome reads codons • tRNA brings in correct amino acids • Protein is built

  48. 12-3: RNA and Protein Synthesis • Translation • ___________ is site of protein synthesis • mRNA strand is _______________ • Ribosome “starts” at the start codon • _______

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