Picornaviruses and myxoviruses Flashcards

exam 4 (37 cards)

1
Q

if the genome is not recognizable to the cell the virion must contain a

A

polymerase enzyme

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2
Q

if a virus needs something to replicate that is not present in the cell, the virus

A

must encode it

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3
Q

small non-enveloped (+) RNA viruses

A

picornavirus

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4
Q

polio

A

picornaviruses

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5
Q

poliovirus has a non-enveloped _________ structure

A

icosahedral

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6
Q

picornavirus entry into cells is internalized by

A

receptor-mediated endocytosis

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7
Q

all picornaviruses initiate translation independent of a

A

5’m7G

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8
Q

translation initiates at an

A

internal ribosome entry site- IRES

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9
Q

polyprotein is cleaved by ___________ into 11-15 individual proteins

A

viral proteases

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10
Q

1 protein rule in eukaryotic cells in picornavirus

A

circumvents canonical 1 mRNA

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11
Q

picornavirus 3D polymerase requires

A

VpG-UU primer

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12
Q

all picornavirus RNAs have a

A

5’VpG

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13
Q

synthesis of (+) RNA is 30-70 times more efficient than synthesis of

A

(-) RNA intermediate

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14
Q

picornavirus assembly occurs in the

A

cytoplasm

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15
Q

picornavirus translation is initiated by a

A

5’cap-independent mechanism

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16
Q

myxoviruses subdivided by antigenicity of the surface proteins

A

Hemagglutinin (HA) and Neuraminidase (NA)

17
Q

genome is 12kb, single-stranded, 8 segmented (-) RNA

18
Q

enveloped, cylindrical capsid and variable in size

19
Q

coats the genomic RNA

A

nucleoprotein (NP)

20
Q

ordered array of protein just below the membrane

21
Q

envelope

A

viral membrane

22
Q

infleunza enters the cell through an

A

endocytic pathway

23
Q

attachment of the influenza to cell surface occurs via the interaction between

A

hemaghlutinin and siliac acid

24
Q

SNATCH

A

viral proteins snatch the 5’ cap from cellular mRNAs

25
capped mRNA fragments are used as primers to initiate
transcription of viral RNA
26
Poly A tail is added by the
viral polymerase
27
viral MRNA are then exported from the nucleus for
translation
28
protects genomic RNA from detection by the cell
NP protein
29
NP protein must return to the
nucleus after translation
30
viral proteins have ____________ recognized by the cell
import signals
31
MI
matrix protein
32
cleaves receptor that contains sialic acid
neuraminidase
33
inhibits neuraminidase by competing with sialic flu
oseltamivir (tamiflu)
34
cell becomes infected with multiple different strains. Genome segments shuffle, generating many different variants
antigenic shift
35
mutations also arise randomly leading to loss or gain of fitness and changes to antigenicity
antigenic drift
36
myxovirus: | enveloped virion that enters cells by fusing its membrane with the
cellular endosomal membrane
37
why is avian flu hard to happen?
different saliac acid