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Virology Midterm 1

  1. What are some benefical roles of viruses?
    gene therapy, phage therapy, vaccine develop
  2. vaccines protect against?
    disease, prevent cancer, pest control, phage therapy
  3. which viruses are ancient?
    polio,smallpox,rabies
  4. chinese treated small pox with what technique?
    variolation
  5. aztecs exposed to which viruses?
    smallpox and measels
  6. when was small pox erradicated?
    1974
  7. who invented smallpox vaccine?
    Jenner
  8. When did jenner make pox vaccine?
    1798
  9. when did who declare war on pox?
    1967
  10. why did polio return?
    sanitation, swers, age acquirement due to NO MATERNAL ANTIBODY
  11. what are the stages of viral discovery?
    discover virus, biochemical analysis, molecular analysis, recombinant tech.
  12. 1st virus to be imaged?
    TMV
  13. 3 viral origin theories?
    1. REgression 2. Modification 3. co-evolution
  14. can have virus have both dna and rna?
    no
  15. speed of organism infections
    • bacteria=minutes
    • animals=hours
    • plants=days
  16. ssDNA viruses common in:
    phage,animal
  17. ds dna common in bacteria animal viruses? t/f
    t
  18. Are all dsRNA viruses segmented?
    yes and in animals.
  19. mRNA has positive polarity if it's 5-3 t/f?
    T
  20. does negative DNA strand code for mRNA?
    yes
  21. almost all dna viruses are dsDNA except
    parvoviradae
  22. almost all RNA viruses are single stranded except
    reoviradae
  23. avg mw of a.a.?
    110
  24. avg mw of on base?
    350
  25. avg mw of base pair?
    700
  26. a protein subunit is one protein
    yes
  27. a structural unit also called a protomer is 1 or more proteins t/f
    t
  28. morphological unit or capsomere was first observed by electron mic?
    yes
  29. capsid is outter unit that what?
    surrounds genome
  30. nucleocapsid is what?
    capsid plus the genome
  31. how many axis of symetrry for helical?
    1
  32. how many axis of symetry for icosahedral?
    3
  33. icosahedran has 20 faces and 12 vertices t/f
    t
  34. poxvirus has complex symmetry?
    yes
  35. what are the three functions of viral particles?
    1. protection 2. recognition 3. initiation
  36. 4 ways to classify a virus?
    type of n.a., ss or ds?, envelope, symmetry
  37. Plant virus common features:
    RNA, non envelpoed, both symmetries
  38. animal virus common features:
    both rna and dna, both enveloped and non, both symmetries
  39. common phage features:
    dna, no envelope, more icosahedral then helical
  40. DNA is mostly segmented in viruses?
    FALSE
  41. most plant viruses have positive strand rna?
    true
  42. monocistronic?
    1 mRNA = 1 protein
  43. if orf's are in a series are they in same reading frame?
    yes
  44. what does 5' cap do?
    facilitates synthesis of proteins, protectgs rna, splicining, transport nucleus
  45. in viruses, what do the linked proteins at 5' end serve as?
    a primer
  46. what does a poly A tail do?
    increase stability
  47. trna structure on virus genome purpose?
    unknown
  48. 3 functional sequences purpose of virus genome?
    1. transcribe for protein 2. translate for protein. 3. genome replicatoin
  49. where are cis acting elements located?
    3' and 5' non coding areas
  50. where are trans acting elements located?
    proteins ac on sequence to enhance replication at ends.
  51. what does leader sequence do and contain?
    ahead of start codon, in non coding areas. Contains ribosome binding site and enhancer sequence.
  52. Instead of a 5' cap a virus will use a
    IRES
  53. where do promoters go for each strand type?
    near 3' end for both positive RNA and negative RNA so as to get -RNA and positive RNA respectively. Can also go internal for subgenomic sequence.
  54. Where is rna dependent rna polymerase found and for what?
    negative rna viruses carry it with them to get the positive strand.
  55. what are the strategies for multiple proteins in a limited viral genome?
    frameshift, read through, polyprotein, subgenomic, multipartile genome
  56. polyprotein products are cleaved with proteolytic action?
    yes
  57. read through represented with a colon?
    yes
  58. multipartile genome will have two genomic dna's?
    yes
  59. where are the factors that control gene expression located?
    upstream 5' end.
  60. promoter consist of:
    regaulatory sequence, initiatior sequence, TATA sequence
  61. dsDNA promoter features:
    promoter at 3' end, enhancer sequence, st and stop sequence
  62. where does replication start in linear genomes?
    3' end
  63. characters of viral proteins?
    structure, transmission, viral encoded enzymes with translational and transcriptional, enzymes to cleave proteins, primer for rna sequence VPG, cap enzymes, interfering proteins for immune dfense
  64. protomers arranged as pentamer at vertex t/f
    t
  65. purpose of viral membrane proteins?
    entry to cell, fusion to cell, antgenic sites, enzymatic activity
  66. forms of viral membrane proteins?
    matrix, glyco, external glyco, transport
  67. how does virus get in gram positive bacteria?
    target teichoic acid antigenic site
  68. how does virus get in gram negative bacteria?
    target lps O antigenic site
  69. how does virus get in plant cell wall?
    trauma
  70. primary tissue culture
    cell line
    subculture
    doubling
    sensecense
    • direct isolation from tissue
    • primary harvesting for individual cell types
    • transfer to keep density low
    • 2 fold increase in population
    • die after fixed replications
  71. do viruses grow exponentially?
    no
  72. can rickettesia or chlamydia grow on non living medium?
    no
  73. do enveloped viruses have to kill host?
    no
  74. can genome have nicks, supercoils or closed ends?
    yes
  75. how may reading frames possible from one ORF?
    3
  76. which virus has wedge shape capsomere?
    polio and rhinovirus
  77. naked negative rna is infectious?
    no
  78. mrna from orf?
    no
  79. viruses in this family largest effector on humans
    small pox, poxviradae
  80. designation sequence for rna d. rna poly?
    3' promoter with vpg
  81. morphological units observed with electron mic?
    yes
  82. rna genomes long or short generally?
    shorter
  83. where does polyermase bind? Ribosome?
    promoter and ribosome binding site
  84. purpose of UTR's?
    contain regulatory sequences, enhancers, promoters etc.
  85. what is a promoter?
    reigion that initiates transcription of a gene.
  86. direction that rna poly works?
    5' to 3'
  87. why particle weight not mw?
    multiple componets
Author
Dynomightdave89
ID
235221
Card Set
Virology Midterm 1
Description
Midterm one questions.
Updated

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