Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Emma > Micro Viruses > Flashcards

Micro Viruses Flashcards

1
Q

picornavirus diseases

A
  • Rhinovirus
  • Hep A
  • GI disease (Coxsackie)
  • Heart Disease
  • foot and mouth disease
  • severe respiratory infection
  • poliomyelitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

picornavirus structures

A
  • very small
  • 1 protein repeats for capsid
  • NON enveloped
  • ss (+) RNA
  • 5’ VpG cap
  • polyprotein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

picornavirus entry

A

-RME

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

picornavirus translation

A
  • by host machinery
  • VpG cap
  • translation initiates at IRES

poly protein –> protease, capsid, replicase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

picornavirus genome replication

A
  • 3D RNAP from virus
  • needs VpG-UU primer
  • makes (-) sense antigenome
  • makes (+) sense genome
  • more efficient to make (+) than (-) RNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

assembly/release of picornavirus

A
  • assembly in cytoplasm
  • (+) RNA encapsulated
  • unclear release – leaves cell destroyed, LYSIS OF HOST CELL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

myxovirus structure

A
  • segmented (-) RNA
  • no cap/tail –> seen as foreign if no NP association
  • enveloped
  • surface proteins: hemagluttinin (HA), neuraminidase (NA)
  • cylindrical (variable in size)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

myxovirus entry

A
  • HA and sialic acid interact to attach

- RME

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

myxovirus transcription/genome replication

A
  • viral proteins steal 5’m7G cap from host mRNA –> used as primers to make (+) viral mRNA.
  • exported from nucleus
  • transcribed back into (-) RNA to replicate genome
  • associates with NP so it isn’t “foreign”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

myxovirus assembly/release

A
  • assembly at plasma membrane
  • buds off
  • neuraminidase cleaves receptor on host cell to prevent reattachment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

tamiflu/oseltamivir

A
  • inhibits neuraminidase
  • budded virions stay bound to same cell (not released)
  • competes with sialic acid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

myxovirus reassortment/mutation

A
  • antigenic shift: two viruses infect, genomes shuffle
  • antigenic drift: mutations arise randomly

Both occur at same time, constantly –> high diversity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

papilloma virus structure

A
  • non enveloped
  • 2 protein capsid (L1, L2 –> req for penetration)
  • dsDNA (circular, histones)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

papilloma entry into cells

A
  • attach to HSPG on basement membrane (exposed at sites of trauma)
  • infection starts in basal layer
  • RME
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

papilloma early gene expression

A
  • E1
  • E2: master regulator
  • E6: binds p53, prevents apoptosis
  • E7: binds Rb, triggers cell division
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

papillomavirus genome replication

A
  • NOT integrated into host genome
  • E1, E2 recruit host machinery
  • replicated once per cell cycle (natural amount)
  • in differentiated epithelial cells: E6, E7 activate DNA synthesis of ONLY viral genome
17
Q

papilloma late gene expression

A
  • ONLY in terminally differentiated keratinocytes
  • DNA replication
  • differential splicing for L1, L2 capsid proteins
18
Q

papillomavirus assembly/release

A
  • L1, L2 transported to nucleus
  • DNA packaged into capsid
  • virions released during natural life cycle of cell (differentiate, die, slough off)
  • no need to lyse cell
19
Q

HPV16,18 transformation in cervical epithelium (oncogenesis)

A
  • RARE
  • integrates part of genome into host
  • selection for cells with E6, E7, but NOT E2 (unregulated, triggers cell division, prevents apoptosis)
  • no virion production (rest of viral genome lost or deleted
20
Q

retrovirus structure

A
  • enveloped
  • ss(+) RNA
  • Gag: capsid proteins
  • Pol: protease (PR), reverse transcriptase (RT), integrase (IN)
  • Env: envelope glycoprotein
21
Q

retrovirus entry

A
  • fusion of viral and cellular membranes
  • *NOT via RME
  • reverse transcription occurs immediately
22
Q

retrovirus genome replication

A
  • reverse transcription catalyzed by viral RT
  • host tRNA primes
  • RT synthesizes wrong direction first
  • uses segment to synthesize correct direction
  • makes (-) DNA
  • makes dsDNA
  • LTR regions become identical, form LTR circle
  • new ds DNA imported into nucleus, integrated into host genome by viral integrase
  • into random location
23
Q

retrovirus assembly/release

A
  • viral proteins targeted to plasma membrane
  • proteins assemble in a curvature
  • bud off
  • cell survives
  • not infectious until MATURATION (viral protease cleaves Gag, Pro)
24
Q

retroviral oncogenesis

A

1) viral inserts upstream of a proto-oncogene

2) viral genome already contains an oncogene

25
Q

All capsids are icosahedral except…

A

Myxovirus –> helical nucleocapsid

26
Q

Retrovirus examples

A

Rous sarcoma virus, HIV, FeLV

Emma (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions