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Molecular Genetics Review - Significance of Griffith Experiment & Hershey & Chase Experiment

This review explores the significance of the Griffith Experiment in proving bacterial transformation and the controversy of whether it was protein or DNA. It also discusses the Hershey & Chase Experiment, which demonstrated that DNA, not protein, is passed on from one generation to another.

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Molecular Genetics Review - Significance of Griffith Experiment & Hershey & Chase Experiment

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  1. SBI4U Molecular Genetics Review Explain the significance of this experiment

  2. SBI4U Molecular Genetics Review Griffith Experiment proved bacterial transformation occurred through a physical, heritable means: but, was it protein or DNA? Still not conclusive…

  3. SBI4U Molecular Genetics Review Explain the significance of this experiment

  4. SBI4U Molecular Genetics Review 35S 32P Hershey & Chase Experiment Demonstrates that it’s DNA, not protein, passed on from one generation to another: 35S not found in offspring virus 32P present in offspring virus

  5. SBI4U Molecular Genetics Review Another Look at the Hershey & Chase Experiment

  6. W SBI4U Molecular Genetics Review Z V U U. DNA Nucleotide V. Phosphate W.Adenine X.Cytosine Y. Gene Locus, DNA backbone Z. Hydrogen bonds Y X

  7. SBI4U Molecular Genetics Review Avery & MacLeod Experiment: If you damage DNA, you destroy heredity.

  8. SBI4U Molecular Genetics Review Match-up Question: Meselson & Stahl = C Chargaff = G Meischer = E Franklin = A Watson & Crick = H Hershey & Chase = F Avery, MacLeod, McCarty = D Griffith = B

  9. SBI4U Molecular Genetics Review A Amino Acid B tRNA C Anticodon E mRNA F Ribosome G Polypeptide Identify the labeled structures:

  10. SBI4U Molecular Genetics Review 1 Lagging Strand 2 Leading Strand 3 DNA pol. 4 Ligase 5 RNA Primer 6 Primase 7 Okazaki fragment 8 DNA pol. 9 Helicase 10 ssb’s 11 Gyrase Identify the labeled structures:

  11. SBI4U Molecular Genetics Review Review Booklet – 6.4 DNA Replication & Repair Q 1: Replication is more suitable because it conveys not only the precision required, but also the semi-conservative nature of DNA synthesis: “half old, half new” Q 3: Table 1 information: R.O: the starting point, at an RNA primer H: Unzips DNA strands R.F: point of DNA strand separation T: aka gyrase; untwists DNA helix SSB: loosely bound to DNA strands, prevent reannealing R.B.: gap between two replication forks

  12. SBI4U Molecular Genetics Review Review Booklet – 6.4 continued Q 4: Table information: NT: provides bases for the nucleotides PB: strong covalent bond of DNA backbone RNAp: builds a primer needed for DNApol RNA primer: provides attachment pt for DNApol DNApolIII: extends the DNA chain LdS: 5’  3’ direction, continuous synthesis LgS: 3’  5’ orientation, discontinuous syn. OF: short DNA strands of Lagging strand DNApolI: aka RNAse H; removes primer Ligase: joins Okazaki fragments

  13. SBI4U Molecular Genetics Review Review Booklet – 6.4 continued Q 5: Table information: Bp mismatch leads to a bulge or twist in the DNA double helix. The weakened point could lead to a gross chromosomal mutation. DNA repair complex, involves DNApol II & I; able to ‘edit’ point mutations in most cases by excising incorrect nucleotide, replacing w correct one. Q 6: Diagram Labels: 1. Helicase & Gyrase 2. Replication Fork 3. SSb’s 4. Ligase 5. point of ligation 6. DNA Polymerase III 7. Template strand 8. 9. Okazaki fragments 10. RNA primer 11. Primase

  14. SBI4U Molecular Genetics Review Review Booklet – 7.2 Transcription & 7.3 Translation Q 1: Table information: Promoter + TATA Box: site of RNA polymerase binding RNA Polymerase: synthesis of new mRNA strand Coding strand: DNA strand NOT being transcribed. 5’ 3’ Template strand: 3’  5’ strand of DNA that IS being transcribed. *it must be this strand in order to ensure mRNA is made in 5’  3’ direction Start Codon: TAC triplet that indicates start point of transcription Q 2: uh….. Transcription, perhaps? Give us some credit, textbook. Q 1: tRNA is much shorter than mRNA Q 2: why yes, I do have a picture to show you!

  15. SBI4U Molecular Genetics Review Review Booklet –7.3 Translation Q 3: Anticodon sequences will be: CAA, CGG, UUU, GGA Q 4:This is a property of the code called Code Redundancy. A limited set of bases in the ribonucleotides (A, C, G, U) can be rearranged into 61 codons (64, with the stop codons!) for the 20 amino acids. Proteins are built out of a limited ‘alphabet’ of 20 amino acids by repetition and duplication of them, as needed. Q 5: A Ribosome is made of two different parts, called the small and large ribosomal subunits. mRNA threads through a ribosome. A tRNA molecule, with an amino acid attached to it and the anticodon that pairs with the amino acid’smRNA codon, introduces the amino acid to be added to the polypeptide chain next. The amino acid is added to the chain and the tRNA is released. Other tRNA molecules add subsequent amino acids to the polypeptide. And that, children, is the world’s lamest fill in the blanks paragraph. #aminoacid

  16. SBI4U Molecular Genetics Review Review Booklet – Chapter 7 summary Q 5: Transcription diagram: DNA b. RNA polymerase c. mRNA Q 6: Translation diagram: Ribosome b. mRNA anticodons d. codon e. Ribosomal large subunit, A site f. P Site g. E site h. polypeptide i. tRNA

  17. SBI4U Molecular Genetics Review Review Booklet – short answer questions Q 1: DNA excision (cutting) by restriction enzymes, and complementary pairing Q 2: Bacteria conjugate, Viruses transfer plasmids to host cells Q 5: Introduction of desirable traits into crop plants or farm animals Q 6: By creating transgenic bacteria to produce clotting factor much more quickly in a lab setting Q 7: Paternity testing; criminal forensics; paleobiology; taxonomy; identification of missing persons, etc.

  18. SBI4U Molecular Genetics Review Review Booklet – short answer questions Q 9 - 20: Matching Test 9B 10C 11E 12A 13B 14D 15C 16B 17E 18B 19C 20B Q 21: A Q 22: E Q 23: B Q 24: E Q 25: B Q 26: B Q 27: E

  19. SBI4U Molecular Genetics Review Review Booklet – short answer questions Q 4-13: 4A 5B 6A 7B 8A 9B 10B 11B 12A 13B Q14-21: 14B 15B* (really all of them!) 16A 17B 18C 19A 20B 21B Q22: ACGGAAUCUUC Q23. Initiation: Binding of mRNA to Ribosome, translation begins; Elongation: adding a.a. to the polypeptide; Termination: release of ribosome when STOP codon reached.

  20. SBI4U Molecular Genetics Review Review Booklet – short answer questions Q 25-29: 25C 26A 27A 28B,D 29D Q30: Absence of Lactose: Repressor protein is free to bind to DNA & prevent transcription. Presence of Lactose: Repressor protein is disabled by Lactose, changed shape prevents it from binding to DNA – transcription proceeds as RNA polymerase binds to DNA. Q31. Exons = coding; Introns = junk DNA. Q32. Promoter = identifies beginning of gene locus, binds RNA polymerase; Enhancer = binds proteins that enhance (improve, promote) transcription. Q 34: A Q 35: A

  21. SBI4U Molecular Genetics Review Review Booklet – short answer questions Q 6,7,8: See notes on DNA discovery! Q 9: TCCAGTTACGCG Q 10: Semi-conservative: half old, half new; template DNA opens up & is copied by enzymes, producing two new DNA molecules, each consisting of one template strand & one new. Q12-16: 12D 13B 14C 15A 16E Q17. C Q 18: B or D both valid Q19: C Q 20: E Q 21: D

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