MIP 420 EXAM 1 || 100% Errorless.
Variolation correct answers Inoculation of individual with material from a smallpox posture
i.e. the 1st vaccines
Discovery of Viruses correct answers 1. Tobacco Mosaic Disease -- viral agents are smaller
than bacteria via filtration
2. Passed cancer from chicken-to-chicken via a filter as well
The Nature of Viruses correct answers -Small in size
-Filterable agents
-Viral genome surrounded by a protein coat
-Obligate intracellular pathogens
-Virions are formed by self-assembly from newly synthesized comments
The Structure of Viruses correct answers -Isocahedral: appear spherical
-Helical: capsid with a hallow tube
-Naked: just the capsid protein
-Enveloped: isocahedral or helical structure surrounded by a lipid bilayer member
-Complex: i.e bacteriophage
Major Structural Components of a Virion correct answers 1. Genome
2. Capsid or Nucleocapsid
3. Envelope
Capsid and Envelope = structural proteins
Virion correct answers Complete infectious virus particle; mostly when outside the cell
Capsid correct answers Protein shell surrounding genome
Built of identical copies of a small number of proteins which arrange to void max contact,
held together by non-covalent bonds
Nucleocapsid correct answers Nucleic acid-protein assembly; packaged within the virion
Structure and Complexity of Viral Genomes correct answers 1. DNA or RNA genome
2. Circular, linear, or segmented
3. ds genome
-DNA or RNA
4. ss genome
-DNA viruses
-RNA viruses
-(+) strand
,-equal to mRNA
-(-) strand
-complementary
to mRNA
Information contained within the Viral Genome correct answers -Genes that encode viral
proteins
-Structural
-For Replication
-Modify Host Cell
-Regulatory signals and sequences
-Assembly and packaging
of genome
-Regulation of replication
cycles
Positive-Strand RNA Genome correct answers -Equal to mRNA
-Genome may be directly
translated on host cell
ribosomes upon entry
-EXCEPTION: retroviruses
-5' Cap: binds to ribosome
-Poly-A Tail: translation and
determines half-life
-Overcomes the 1 protein per
mRNA problem in
Eukaryotic cells by making
one long piece of DNA then
cleaving it at points where
restriction enzymes can cut
for specific proteins
Helical Symmetry correct answers Nucleocapsids of viruses appear rod-like or filamentous
-16.3 coat protein molecules per turn; Each coat protein binds 3 nucleotides
Icosahedron Symmetry correct answers A solid with 20 triangular faces and 12 vertices,
which are related by 2-, 3-, and 5-fold axes of rotational symmetry
2-fold axes: passes through
the edges
3-fold axes: extend through
the center of
each face
5-fold axes: through each of
the vertices
Simplest Icosahedral Capsid correct answers Built by using identical subunits to form each
triangular face
,-Smalest number of subunits = 60; would require 3 units on each triangular face
Ex: Parvoviridae; 60 copies of a single subunit VP2
Structurally Complex Capsids correct answers Ex: Adenoviridae
Fibers projecting from the 5-fold axis of symmetry
Enveloped Viruses Components correct answers Lipid Bilayer - acquired from host cell
during assembly
Viral Glycoproteins - integral membrane proteins
Viral Glycoproteins correct answers --from spikes or other projections on the exterior surface
of the virion
--binding site for cell surface virus receptors (host cell binding)
--major antigenic determinant
--mediate fusion of the viral envelope with celluar membranes during entry
--Enzymatic activities
--internal domains make contact with components of virion
Virus-Encoded Enzyme: RdRp correct answers RNA Dependent RNA Polymerase
Reads RNA, makes RNA
Present in RNA viruses
--(+)RNA: can make it in cell
--(-)RNA: have to carry it in virion
Virus-Encoded Enzyme: Reverse Transcriptase correct answers Synthesis of viral DNA from
RNA template
Present in:
-Retroviruses: in cell; carry RNA into the cell
-Hep B: in virion; package RNA then bring DNA into the cell
Virus-Encoded Enzyme: Proteases correct answers Beaks down proteins and peptides
Virus-Encoded Enzyme: Integrase correct answers Puts DNA into host cell genome
--Retroviruses
Cellular Histones correct answers Package Polyomaviridae and Papillomaviridae viral DNA
Cellular Transfer RNA (tRNA) correct answers Serves as the primer for Retroviruses
replication
Classification of Viruses correct answers -Nature of the nucleic acid in the virion
-Symmetry of the capsid
, -Naked or Enveloped
-Nature of diseases they cause
-Strategy of viral replication ("Baltimore Scheme")
Virus Nomenclature correct answers Order - Virales
Family - Viridae
Subfamily - Virinae
Genus - Virus
Retrovirus correct answers ss(+)-sense RNA virus with a DNA intermediate
Replicates in the cytoplasm
--uses its own RT to produce DNA from its RNA
(+)-Strand RNA Viruses (ss) correct answers Caliciviridae
Coronaviridae
Flaviviridae
Picornaviridae
Togaviridae
Retroviruses
(-)-Strand RNA Viruses (ss) correct answers Arenaviridae
Bunyaviridae
Filoviridae
Orthomyxoviridae
Paramyxivurudae
Rhabdoviridae
DNA Viruses correct answers Adenoviridae
Hepadnaviridae
Herpesviridae
Papillomaviridae
Parvoviridae
Polymoaviridae
Poxviridae
RNA Viruses correct answers Arenaviridae
Bunyaviridae
Caliciviridae
Coronaviridae
Flaviviridae
Filoviridae
Orthomyxoviridae
Paramyxoviridae
Picornaviridae
Reoviridae
Rhabdoviridae
Variolation correct answers Inoculation of individual with material from a smallpox posture
i.e. the 1st vaccines
Discovery of Viruses correct answers 1. Tobacco Mosaic Disease -- viral agents are smaller
than bacteria via filtration
2. Passed cancer from chicken-to-chicken via a filter as well
The Nature of Viruses correct answers -Small in size
-Filterable agents
-Viral genome surrounded by a protein coat
-Obligate intracellular pathogens
-Virions are formed by self-assembly from newly synthesized comments
The Structure of Viruses correct answers -Isocahedral: appear spherical
-Helical: capsid with a hallow tube
-Naked: just the capsid protein
-Enveloped: isocahedral or helical structure surrounded by a lipid bilayer member
-Complex: i.e bacteriophage
Major Structural Components of a Virion correct answers 1. Genome
2. Capsid or Nucleocapsid
3. Envelope
Capsid and Envelope = structural proteins
Virion correct answers Complete infectious virus particle; mostly when outside the cell
Capsid correct answers Protein shell surrounding genome
Built of identical copies of a small number of proteins which arrange to void max contact,
held together by non-covalent bonds
Nucleocapsid correct answers Nucleic acid-protein assembly; packaged within the virion
Structure and Complexity of Viral Genomes correct answers 1. DNA or RNA genome
2. Circular, linear, or segmented
3. ds genome
-DNA or RNA
4. ss genome
-DNA viruses
-RNA viruses
-(+) strand
,-equal to mRNA
-(-) strand
-complementary
to mRNA
Information contained within the Viral Genome correct answers -Genes that encode viral
proteins
-Structural
-For Replication
-Modify Host Cell
-Regulatory signals and sequences
-Assembly and packaging
of genome
-Regulation of replication
cycles
Positive-Strand RNA Genome correct answers -Equal to mRNA
-Genome may be directly
translated on host cell
ribosomes upon entry
-EXCEPTION: retroviruses
-5' Cap: binds to ribosome
-Poly-A Tail: translation and
determines half-life
-Overcomes the 1 protein per
mRNA problem in
Eukaryotic cells by making
one long piece of DNA then
cleaving it at points where
restriction enzymes can cut
for specific proteins
Helical Symmetry correct answers Nucleocapsids of viruses appear rod-like or filamentous
-16.3 coat protein molecules per turn; Each coat protein binds 3 nucleotides
Icosahedron Symmetry correct answers A solid with 20 triangular faces and 12 vertices,
which are related by 2-, 3-, and 5-fold axes of rotational symmetry
2-fold axes: passes through
the edges
3-fold axes: extend through
the center of
each face
5-fold axes: through each of
the vertices
Simplest Icosahedral Capsid correct answers Built by using identical subunits to form each
triangular face
,-Smalest number of subunits = 60; would require 3 units on each triangular face
Ex: Parvoviridae; 60 copies of a single subunit VP2
Structurally Complex Capsids correct answers Ex: Adenoviridae
Fibers projecting from the 5-fold axis of symmetry
Enveloped Viruses Components correct answers Lipid Bilayer - acquired from host cell
during assembly
Viral Glycoproteins - integral membrane proteins
Viral Glycoproteins correct answers --from spikes or other projections on the exterior surface
of the virion
--binding site for cell surface virus receptors (host cell binding)
--major antigenic determinant
--mediate fusion of the viral envelope with celluar membranes during entry
--Enzymatic activities
--internal domains make contact with components of virion
Virus-Encoded Enzyme: RdRp correct answers RNA Dependent RNA Polymerase
Reads RNA, makes RNA
Present in RNA viruses
--(+)RNA: can make it in cell
--(-)RNA: have to carry it in virion
Virus-Encoded Enzyme: Reverse Transcriptase correct answers Synthesis of viral DNA from
RNA template
Present in:
-Retroviruses: in cell; carry RNA into the cell
-Hep B: in virion; package RNA then bring DNA into the cell
Virus-Encoded Enzyme: Proteases correct answers Beaks down proteins and peptides
Virus-Encoded Enzyme: Integrase correct answers Puts DNA into host cell genome
--Retroviruses
Cellular Histones correct answers Package Polyomaviridae and Papillomaviridae viral DNA
Cellular Transfer RNA (tRNA) correct answers Serves as the primer for Retroviruses
replication
Classification of Viruses correct answers -Nature of the nucleic acid in the virion
-Symmetry of the capsid
, -Naked or Enveloped
-Nature of diseases they cause
-Strategy of viral replication ("Baltimore Scheme")
Virus Nomenclature correct answers Order - Virales
Family - Viridae
Subfamily - Virinae
Genus - Virus
Retrovirus correct answers ss(+)-sense RNA virus with a DNA intermediate
Replicates in the cytoplasm
--uses its own RT to produce DNA from its RNA
(+)-Strand RNA Viruses (ss) correct answers Caliciviridae
Coronaviridae
Flaviviridae
Picornaviridae
Togaviridae
Retroviruses
(-)-Strand RNA Viruses (ss) correct answers Arenaviridae
Bunyaviridae
Filoviridae
Orthomyxoviridae
Paramyxivurudae
Rhabdoviridae
DNA Viruses correct answers Adenoviridae
Hepadnaviridae
Herpesviridae
Papillomaviridae
Parvoviridae
Polymoaviridae
Poxviridae
RNA Viruses correct answers Arenaviridae
Bunyaviridae
Caliciviridae
Coronaviridae
Flaviviridae
Filoviridae
Orthomyxoviridae
Paramyxoviridae
Picornaviridae
Reoviridae
Rhabdoviridae
