Exam 4

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Exam 4
2012-06-20 22:35:31

Chapters 8 and 9
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  1. Genotype
    Genes that are present in a cell
  2. Phenotype
    the expression of a gene
  3. DNA
    • deoxyribosenucleic acid
    • 4 bases: Adenine-Thymine, Guanine-Cytocine 
  4. RNA
    • ribosenucleicacid
    • 4 bases: Adenine-Uracil, Guanine-Cytocine  
  5. % of DNA that codes vs. non-coding
    • Coding: 2%
    • Non-coding: 98% 
  6. rRNA
    ribosomal RNA
  7. mRNA
    messenger RNA
  8. tRNA
    transfer RNA
  9. 5'-3'
    Sense strand
  10. 3'-5'
    Nonsense strand
  11. DNA Replication
    • Enzyme divides strands of DNA
    • DNA polymerase is used to copy continuously from 5'-3'
    • Okazaki fragments fill in from 3'-5' 
  12. Transcription
    • DNA being copied to mRNA
    • Occurs in nucleus
    • requires RNA polymerase 
  13. Translation
    Ribosome reads mRNA and creates proteins from amino acids coded in mRNA
  14. Exons
    Coding sequences only in eukaryotic DNA
  15. Introns
    Non-coding sequences in eukaryotic DNA that are cut out.
  16. Operon
    structure of a gene
  17. Inducible operon
    an operon that can be turned on and off
  18. Operon Diagram
  19. Positive Regulation
    • cells prefer glucose as a fuel
    • When glucose is present: cAMP levels are low
    • When glucose is absent: cAMP levels are high
  20. Mutation
    • any change in DNA sequence
    • can be good, harmful, neutral or deadly 
  21. Neutral Mutation
    mutation codes for same amino acid, so organism is unaffected
  22. Missense Mutation
    • codes for different amino acid
    • could be good or bad 
  23. Nonsense Mutation
    • adds a premature stop codon
    • usually deadly 
  24. Framshift Mutation
    • addition or deletion of a base, changing sequence after
    • usually deadly 
  25. Spontaneous Mutation rate
    1 in 1,000,000 (10-6)
  26. Mutation causes
    • 1) Spontaneous mutation
    • 2) Mutagens
    • 3) Radiation
    • 4) Certain Viruses 
  27. Mutagen
    • Increases mutation rate by 10-1000x
    • asbestos
    • benzopyrene (burnt stuff)
    • aflatoxin (PB in other contries)
  28. Radiation
    UV and gamma
  29. Effect of UV on DNA
    • sunburn causes thymine dimers. 
    • Two T's attach to each other instead of A's
    • Excision repair fixes it
  30. Example of Mutation Virus
  31. Positive (Direct) Selection
    • ex. testing antiobiotic resistance
    • Putting bacteria on antibiotic plate. If any growth they are antibiotic resistant.
    • Positive selection entails the growing the culture on a medium that will alow for the growth of only the mutant colonies

    .If, for example, we want to find mutants that resistant to penicillin, we grow the culture on a medium that contains pencillin. Only those colonies that are resistant to penicillin will grow and we ca identify them directly 
  32. Negative (In-direct) Selection
    • Negative selection is used to identify mutants that have lost the ability to perform a certain function that their parents had.
    • -Auxotrophic mutants, for example, are bacteria that have lost the ability to synthesize an essential nutrient.

    • The replica-plating technique is used to identify mutants by negative selection.
    •      -the replica-plating technique can be used, for example, to identify mutants that have lost the ability to synthesize the amino acid histidine. Therefore, mutants are His- and require histidine in order to survive.
    • `Inoculate a histidine enriched medium with bateria. Incubate so that cells can form colonies. This is the master plate.
    • `Press a sterile velvet surface into the colonies of the master plate. Some cells from each of the colonies adhere to the velvet.
    • `Prepare two mediums, one with histidine, the other without histidine.
    • `Transfer cells from the velvet to each plate.
    • `Compare growth on the two plates after incubation. Colonies that grow on the histindine enriched medium but not on the medium lacking histidine are His- mutants.
  33. Replica Plating
    using sterile velvet to move organisms to different plates
  34. Ames Test
    • Good at testing out potential carcinogens. 
    • Reverses gene mutations
  35. Transformation
    Uptake of naked DNA
  36. Conjugation
    F+ bacterial cell transfering DNA to F- bacterial cell via pili
  37. Transduction
    • Virus takes over cell and makes new viruses inside infected cell
    • Sometimes they accidently pick up host DNA and bring it to a new host 
  38. Transposons
    • Jumping genes.
    • Segment of DNA that can cut itself out and move to another chromosome
    • Indian corn 
  39. Bacteriocins
    Chemicals some bacteria produce to harm other bacteria
  40. Biotechnology
    • use of microbes for a desired outcome
    • ancient-beer, cheese 
  41. Recombinant DNA Technology
    • moving genes from one organism to another to get the gene expressed
    • new since 1970s
    • first time: putting firefly genes in tobacco to make it glow 
  42. Clone
    identical DNA
  43. Site Directed Mutagenesis
    Trying to mutate cells to create a better geneotype
  44. Restriction Enzymes
    • cut DNA at specific sequences
    • Can be blunt cut or staggered cut 
  45. Plasmid
    a circular vector piece of DNA
  46. Bacteriophage
    viruses that infect bacteria
  47. Polymerase Chain Reaction
    • amplifies DNA from one strand to billions in 3 hours
    • requires heat
    • DNA is split, primers are added and DNA polymerase copies DNA 
  48. Blue White Screening
    Proves that you are successful in getting DNA into e. Coli
  49. No growth Result of B/W screening
    Bacteria did not take up vector
  50. Blue Growth
    Vector got ito bacteria, but not DNA
  51. White Growht
    • Successful!
    • Both Vector and DNA entered cell 
  52. Transformation
    uptake of DNA
  53. Electroporation
    put DNA in test tube and give it an electric shock
  54. Protoplast fusion
    • Enzymatically remove cell walls from 2 cells and put it in dense glycerine solution
    • causes cells to fuse together into 1 cell 
  55. Gene gun
    gun that coats DNA in gold bullets and shoots into cells
  56. Microinjection
    • Injectiing DNA into cell
    • IVF 
  57. Genetic Libraries
    • Holds pieces of DNA and cells
    • DNA is cut up, put in vectors, put in e. coli and deep frozen 
  58. Reverse Transcriptase
    • Turns RNA into cDNA
    • HIV virus 
  59. cDNA
    complementary DNA
  60. Examples of Therpeutic Genetic Engineering
    • Subunit vaccines
    • gene therapy
    • DNA vaccines
    • Gene scilencing
    • HGH
    • Insulin
  61. Examples of Scientific Genetic Engineering
    • proteomics
    • reverse genetics
    • human genome project
    • human microbiome project
    • DNA fingerprinting/forensics
  62. Examples of Agricultural Genetic Engineering
    • more nutritiotous animals and plants
    • dourght resistance
    • salt resisntace
    • pseudomonas syringae-prevents frost damage
    • bacillus thuriengenesis-kills mosquito larvae