bio Exam 3-1

  1. a virus that infects prokaryotic cells
  2. a protein shell that surrounds teh genome of a virus particle
  3. a subunit of a capsid
  4. a virus that relies on another virus, the helper virus, to provide some of its components
    defective virus
  5. a protein synthesized soon after virus infection and before replication of the virus genome
    early protein
  6. a virus that provides some necessary components for a defective virus
    helper virus
  7. cell inside which a virus replicates
    host cell
  8. three-dimensional figure with 20 triangular faces
  9. a protein made later in viral infection, after replication of the virus genome
    late protein
  10. a bacterium containing a provirus
  11. a state following virus infection in which the viral genome is replicated as a provirus along with the genome of the host
  12. a series of steps after virus infection that leads to virus replication and teh destruction (lysis) of the host cell
    lytic pathway
  13. a virus with a single stranded genome that has teh opposite sense to (is complimentary to) the viral mRNA
    negative-strand virus
  14. a zone of lysis or cell inhibition caused by virus infection of a lawn of sensitive cells
  15. a virus with a single stranded genome that has teh same complimentarity as the viral mrNA
    positive strand virus
  16. teh genome of a temperate virus when it is replicating in step with, and often integrated into, the host chromomse
  17. a virus whose RNA genome has a DNA intermediate as part of its replication cycle
  18. the process of copying information found in RNA into dna by teh enzyme reverse transcriptase
    reverse transcription
  19. a virus whose genome is able to replicate along with that of its host withoug causeing cell death in a state called lysogeny
    temperate virus
  20. virion
    infectious particle; the nucleic acid genome surrounded by a protein coat and in some cases other layers of material
  21. a virus that lyses or kills the host cell after infection; a non temperate virus
    virulent virus
  22. a genetic element containing either rna or dna surrounded by a protein capsisd and that replicates only inside host cells
  23. small circular single strandecd rna that causes certain plant diseases
  24. nucleic acid surrounded by protein
  25. inert. doesnt carry out respiration or biosynthesis. how they move from cell to cell
  26. most viruses are either linear or circular
  27. overall viral assembly is a a what assembly
    self assembly
  28. nucleic acid + protein packaged in virion
  29. layers around a nucleocapsid
  30. the way in which capsomers are arranged in virus capsid
  31. 2 types of symmetry
    rod and spherical
  32. helical
  33. icosahedral
  34. which is more efficient, spherical or rod?
    spherical, icosahedral
  35. lipid bilayer + glycoproteins makes inital contact with the cell
    viral envelope
  36. icosahedral head + tails. tail is complex, composed of many proteins
    complex virus
  37. makes a small hole in cell wall. so nucleic acid can enter. made in later stages of infection causes lysis
  38. number of infectious units per volume of liquid
  39. a zone of lysis: clear area. replication of a virion. is formed when cells are lysed
  40. How do you do a plaque assay?
    virus partciles are mixed with host bacterial and spread on a nutrient agar medium and then incubated adn then count the number of plaque forming units
  41. know how concentrated a viral suspension needs to be to yield a certain number of plaques
    efficiency of plating
  42. 5 steps for viral replication
    • 1. attachment of virion to host cell
    • 2. penetration of virion or nucleic acid
    • 3. synthesis of virus nucleic acid and protein
    • 4. assembly of capsids and packaging of viral genomes
    • 5. release of mature virions
  43. What happens in the 1st few minutes of infection?
    eclipse: infectious particles cant be detected since they are absorbed into host cells viral nucleic acid enters.
  44. begins as nucleic acids are packaged into protein coats. titer rises. virus particles still cant be detected
  45. eclipse + maturaiton
    latent period
  46. mature virions can be released by what 3 ways?
  47. number of virions released
    burst size
  48. how does T4 infect a cell?
    • 1. attach cell fibers
    • 2. then retract and core makes contact with cel wall with tail pins
    • 3. lysozyme forms small pore in peptidoglycan
    • 4. tail sheath contracts and injects dNA
  49. cleaves viral DNA to prevent replication (restriction)
    restriction endonucleases
  50. how do viruses protect DNA?
    methylation and glucosylation so it prevents restriction endonucleases attack
  51. what configuration for mRNA must all viruses have?
  52. semi conservative; dsDNA(+ or -)
    class I
  53. semi conservative (ssDNA +) make of other strand---ds intermediate---discard one-----transcription
    class II
  54. ds RNA +, transcribe the minus strand
    class III
  55. ssRNA (+) used directly as mrna
    class IV
  56. transcription of minus strand of ssrna (-)
  57. ssrna + retrovirus, reverse transcriptase, ds dna intermediate ---transcritption of - strand
    class VI
  58. ds dna (+ or -), transcription followed by reverse transcription
    class VII
  59. soon after infection, help with replication of virus nucleic acids and are made in smaller amounts
    early proteins
  60. make the protein coat, more structural and made in large amounts
    late proteins
  61. several genomic units end to end to make a long dna molecule
  62. enzymes needed dna rep and transcription
    early and middle proteins
  63. proteins of head and tail and liberate phages
    late proteins
  64. recognizes dna sequences in middle promoters and guides them to rna pol
    mot A
  65. lysogens
  66. types of lysogenti viruses
    lambda and p1
  67. helps inactivate lytic pathway
    repressor proteins
  68. CI
    lysogenetic pathway
  69. cro proteins
    lytic pathway
  70. 2 things must happen so lytic pathway does not happen
    • 1? synthhesis of late proteins must be stopped
    • 2. copy of lambda dna must be integrated in host chromosome
Card Set
bio Exam 3-1
Chapter 10 vocab