Virology 1

Front 1

3 naked dna virus families

Back 1

parvo-
papo-
adeno-

Front 2

3 enveloped dna families

Back 2

hepadna-
herpes-
pox-

Front 3

only single stranded dna virus family

Back 3

parvo-
(also the smallest dna virus)

Front 4

only segmented dna virus family

Back 4

hepadna
(hepatitis B)

Front 5

3 naked rna virus families

Back 5

pico-rna (picorna)
calici-
reo-

Front 6

only 2ble stranded rna virus family

Back 6

reo-
(resp, enterir, orphan = rotavirus which initially couldn't be found to cause human dx)

Front 7

2 segmented rna virus families

Back 7

reo-
influenza

Front 8

only rna helical enveloped family that has positive polarity

Back 8

corona-

Front 9

defective hepatitis family
what does it require for replication

Back 9

deltavirus
req HBV for replication

Front 10

what does arenavirus family have on the surface

Back 10

granules on the surface that are nonfunctional ribosomes

Front 11

define capsid

Back 11

outer protein coat made of capsomer subunits

Front 12

2 forms of viral symmetry

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Icosahedral
- capsomers arranged in 20 triangles that form a symmetric sphere-like figure

Helical
- capsomeres arranged in a hollow coil

Front 13

where do viruses obtain the envelope
what is the one exception

Back 13

- from the cell membran of the host cell upon budding

- exception is herpes virus which gets it from the nuclear membrane of the host

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what is the tegument
example

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- btw envelope & nucleocapsid
- incls regulatory proteins such as transcription & translation factors
- ex: HSV & CMV

Front 15

how are route of transmission and envelope presence generally related?

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- envelope generally confers instability
- fecal-oral route generally are naked --> can survive the environment
- blood/sexual/resp droplet generally have an envelope
-exception - rhinoviruses - resp droplets but naked --> survive in environment longer

Front 16

which viruses are 'haploid' & which 'diploid'?

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- all viruses have 1 copy of their genome = haploid

- except retroviruses which have 2 copies = diploid

Front 17

define CPE
examples

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Cyto-Pathic Effect
- change in appearance of virus-infected cell

- giant cell syncytia

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define hemadsorption

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- attachment of erythrocytes to surface of virus-infected cell

- requires hemagglutinin protein on viral envelope

- mumps, parainfluenza, influenza

Front 19

ELISA steps

Back 19

known Ab on plate
pt specimen added
pt Ag binds to known Ab
known Ab + enzyme added
bind pt Ag
substrate added
binds enzyme
quantitate

Front 20

IgM vs. IgG
current infection or not?

Back 20

IgM = current infection
IgG = can't use to diagnose current infection since Ab could be from previous infection

Front 21

define inclusion bodies

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- aggregates of many virus particles

- found in nucleus or cytoplasm of infected cells

Front 22

2 examples of inclusion bodies

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- nuclear inclusions of some herpes viruses

- cytoplasmic inclusions of rabies virus (Negri bodies)

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eclipse period

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- after entry into host cell, virus disappears from cell

- no virus particle, only viral nucleic acids

Front 24

latent period

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onset of infection to extracellular appearance of virus

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early proteins

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enzymes for replication of viral genome

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late proteins

Back 26

structural & capsid proteins

Front 27

what does specificity of attachment determine?

Back 27

- which host cell receptor/protein the virus attaches to

- determines host range of virus & organ-specificity in host

Front 28

stages of viral growth cycle
(8)

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- attachment &
- penetration by parental virion
- uncoating of viral genome
- early viral mRNA & protein synthesis
- viral genome replication
- late viral mRNA & protein synthesis (structural components)
- virion assembly for progeny
- virion release from cell of progeny

Front 29

to what does HSV-1 attach

Back 29

fibroblast growth factor receptor

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to what does rabies virus attach

Back 30

acetylcholine receptor

Front 31

to what does HIV attach

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CD4 protein on helper T lymphocytes

(normal fn is assist Ag binding to class II MHC protein of helper T cell)

Front 32

to what does EBV attach

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complement receptor

Front 33

to what does vaccinia virus attach

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epidermal growth factor receptor

Front 34

to what does rhinovirus attach

Back 34

integrin ICAM-1

Front 35

how does the virus penetrate the cell & where does uncoating take place?

what is the exception?

Back 35

pinocytic vesicle engulfs it and uncoating takes place in vesicle

exception is bacteriophage - injects DNA into cell through tail

Front 36

what is infectious nucleic acid?

Back 36

purified viral DNA or RNA without any protein that can carry out the entire viral growth cycle and produce complete virus particles

Front 37

where do DNA viruses replicate
what is the exception?

Back 37

- DNA viruses replicate in the nucleus

- exception = poxviruses
replicate in the cytoplasm bc they carry their own polymerase

Front 38

what kind of DNA is in all DNA viruses?
what is the exception?

Back 38

- the DNA in all DNA viruses is dsDNA (double-stranded)
- exception is parvo-
they have ssDNA (single stranded)

Front 39

what is ambisense?

Back 39

RNA segments with both +ve & --ve polarity regions

Front 40

what is positive polarity in RNA viruses?

Back 40

RNA with the same base sequence as mRNA

use the viral RNA genome directly as m RNA

Front 41

what is negative polarity in RNA viruses?

Back 41

RNA with base sequence complimentary to mRNA

Front 42

DNA viruses use which RNA polymerase for replication?

what are the exceptions?

Back 42

- use host cell DNA-dependent RNA polymerase to synthesize their m RNA
- exception 1 = poxviruses
carry virion polymerase
- exception 2 = hepadnavirus
has ssDNA section --> virion DNA polymerase to synthesize missing DNA portion
then host cell RNA polymerase for mRNA synthesis

- exception 3 = parvovirus
host cell DNA polymerase --> viral dsDNA then host cell RNA polymerase

Front 43

what are the 4 groups for RNA virus synthesis of mRNA?

Back 43

1) ssRNA +ve
use virion RNA directly
2) ssRNA -ve
virion RNA polymerase
3) dsRNA
virion polymerase
4) retrovirus
ssRNA +ve but use virion DNA polymerase to make DNA copy of virion RNA --> integrated into host DNA then later use host RNA polymerase for viral mRNA

Front 44

what is a reverse transcriptase and which viruses use it?

Back 44

RNA-dependent DNA polymerase makes DNA from RNA

1) HIV - early in cycle use viral RNA genome to synthesize DNA intermediate

2) hepadnaviruses (ex: HBV) - late in cycle use RNA intermediate to synthesize viral DNA genome

Front 45

what is a replicase and how is it used?
what are the exceptions?

Back 45

replicase is a virus-encoded polymerase that replicates the genome for progeny viruses

- parvovirus B19, HPV use cell DNA polymerase

- HIV, HTLV use cell RNA polymerase