Viruses Flashcards
1
Q
Homosexual white couples in Africa?
A
sub-type B
2
Q
Polydnavirus
A
Transferred by a wasp to a caterpillar along with eggs
3
Q
Picornaviridae poliovirus
A
(+) ssRNA
ready to go
causes paralyzing poliomyelitis, there is currently an outbreak in Syria
4
Q
How many subunits are in the Norwalk virus?
A
180
5
Q
Poxviridae variola virus
A
dsDNA (100-370 kbps) and causes the smallpox virus
6
Q
What is the outer covering of the reovirus?
A
No envelope.
Release at late endosome
7
Q
HIV-1 subtype in N.A.?
A
B
8
Q
What is virus shedding?
A
Release of virions from infected individuals
9
Q
Proviral DNA
A
Integrated into host genome by HIV virus
10
Q
How many pentamers does Poliovirus have?
A
12 (60 faces in total of 3 proteins each)
Perfectly icosahedral
11
Q
Two types of flaviridae
A
Dengue virus, West nile
12
Q
VP1, VP2, VP3
A
capsid proteins of Poliovirus
13
Q
Outer covering of Influenza?
A
Envelope
14
Q
Where was the Measles outbreak?
A
Indiana
15
Q
Env gene
A
encodes glycoproteins gp120 and gp41
16
Q
A
17
Q
Does ebola have a lipid envelope?
A
Yes
18
Q
Pol gene
A
integrase, RT, protease to cut polyprotein
19
Q
What HIV-1 subtype is most prevalent in Africa?
A
C
20
Q
Polyomaviridae JCV
A
dsDNA (5 kbps)
Infects 80% of north americans, only pathogenic (causing neurodegenerative diseases) if immunodeficient
21
Q
What are the lentivirus subtypes (3)?
A
HIV-1 and HIV-2
ALSO SIV cpz
22
Q
What are possible numbers of subunits in a virus with polyhedral symmetry?
A
60, 180, 240, 960
23
Q
What is tougher, an enveloped or non-enveloped virus?
A
Non-enveloped (likely to be transmitted through the alimentary tract)
enveloped (more likely to be transmitted through aerosols)
24
Q
How is HIV transmitted?
A
Through the lower alimentary tract (anal intercourse)
also through tears in the urogenital tract.
also through the bloodstream (injections)
25
Simian 40 virus
Round, polyhedral symmetry
26
Mimivirus
Can be seen through a light microscope. Cannot pass through the 0.2 micron filter. Host is the amoeba.
27
Polyprotein
HIV, includes Gag, Pol, and Env
28
What are the two types of picornaviridae viruses?
1. Poliovirus
2. Hepatitis A
Both are (+) ssRNA viruses
29
Pneumocystic pneumoniae (fungal pneumonia)
Associated with first cases of AIDS
30
What is the outer covering of Poliovirus?
Icosahedral symmetry with 180 subunits.
60 VP1, 60 VP2, 60 VP3.
VP1 recognizes the host cell receptor. It inserts the hydrophobic 3' N-terminus into the host, forming a channel that allows release of the genome at the plasma membrane.
31
Measles virus
Helical symmetry with a nucleocapsid that interacts with the host genome
32
What shape is an HIV protamer?
Hexagon - 6 subunits per protamer
33
What is SU?
gp120 - the surface protein of HIV
binds CD4
then binds CCR5
then gp41 inserts into membrane
34
Hepadnavirus hepatitis B
Gapped dsDNA
USES VIRAL ASSOCIATED DNAP to fill in the gaps (or reverse transcriptase in cases)
Sexually transmitted
100x more infectious than HIV-1
35
When was the first documented case of AIDS?
Early 80s
36
Parvoviridae parvovirus
ssDNA
uses host enzymes
causes infections of the hematopoietic system, intestinal system, and fetus in animals (cats and puppies)
37
Retroviridae HIV
(+) ssRNA converted to dsDNA, integrated into genome, then dsDNA is transcribed into mRNA, etc.
38
Adenovirus adenoviridae
dsDNA (36 kbps)
Causes respiratory and GI infections
39
Name a quasispecies
Name a virus that shows quasiequivalence
1. HIV due to RT
2. Norwalk virus
40
Herpesviridae
All people are infected. Kissing disease.
Emporer Tiberius. To creep or to crawl.
Transported into the nucleus through microtubules
41
Does poliovirus have a lipid envelope?
No
42
Reovirus
released at the late endosome. Not enveloped.
43
How is hep A transmitted?
Upper alimentary tract
44
What is the flaviridae dengue virus?
a tropical fever transmitted by mosquitos.
Genome is released at the late endosome
45
Filoviridae ebola
(-)ssRNA uses L protein to transcribe into (+)ssRNA
Last outbreak was in 2014
46
karposi sarcoma
rare form of cancer associated with AIDS
47
Gag gene
synthesizes capsid, nucleocapside, p24
48
What viruses release their genome at the plasma membrane? (2)
Poliovirus and HIV
49
What is TM?
fusion protein in HIV: gp41
50
Norwalk virus
quasiequivalent polyhedron - loss of 5-fold axis of symmetry
51
Mark Weinberg, 2000
Brought HAART to more people in Africa
52
Flaviridae WNV
RNA virus, enveloped.
80% are asymptomatic (INAPPARENT), 20% are symptomatic with wild symptoms.
1% have deadly neuroinvasive symptoms causing encephalitis
Which is deadly.
Even if asymptomatic and infection is inapparent, transmission can occur.
Transmitted on a plane. Known by gene sequencing because
Israel WNV was very similar on a phylogenetic tree.
53
Reoviridae rotavirus
dsRNA (which must be transcribed into two copies of positive ss mRNA)
infects 4/5 children in the first 5 years of life
most important cause of gastroenteritis worldwide
most common cause of infantile death in third world countries
54
What class of virus is most likely to be transmitted by fomites?
Non-enveloped virus
55
How big is the HIV genome?
7-10 kb
56
What percentage of Africans are infected with HIV?
1/4
57
Hemagglutinin
Glycoprotein found on orthomyxoviridae influenza, which recognizes host receptor sialic acid
58
What is a virus spread by skin-to-skin contact?
Herpes gladitorum
59
Name viruses that begin as (+)ssRNA ready for translation (4).
1. Picornaviridae polioviris
2. picornaviridae hepatitis A
3. HIV
4. West Nile Virus
60
Paramyxoviridae Measles
- has a cell envelope
- helical symmetry (nucleocapsid)
- releases @ plasma membrane with cell envelope glycoproteins!
61
What is CA?
p24 - the capsid protein of HIV
62
63
Name some viruses transmitted through aerosols in the respiratory system (3).
1. Measles virus
2. Rhinovirus (common cold)
3. Influenza (avian and human)
64
Negative staining
Used in EM - background is stained, specimen is not
65
Why does HIV have so many mutations?
Reverse transcriptase lacks exonuclease activity and cannot fix mistakes. 1-10 nucleotide errors per synthesis!
66
Mousepox
Fenner experiment
67
Vesicular stomatitis virus
Helical symmetry
68
69
NPC1
Cathepsins break down the ebola capsid. NPC1 cholesterol transporter in the LE in Ebola is important for the release of the genome.
70
How many people are infected with AIDS? How many have died? Where is it concentrated to?
39 million
31 million
24 million in sub-saharan africa
71
Rous Sarcoma Virus
Forms foci, therefore a transformation assay can be used to detect infectivity
72
How many proteins are on the HIV capsid?
1500
73
What/when was the first virus discovered, first animal virus discovered, and first human virus discovered?
1. 1800s - TMV
2. 1898 - virus causing foot and mouth disease in animals - Loeffler and Frosch - larger and filterable
2. 1901 - YFV
74
Yellow fever virus
transmitted by mosquitos. doctors inoculated each other with infected mosquitos in 1901. The first human virus.
75
Where are 2-6 sialic acid linkages found in humans? 2-3?
in the upper and lower respiratory tract. 2-3 is found in the lower respiratory tract.
76
What viruses release their genomes from the late endosome?
Reovirus
Ebola (NPC1)
Dengue virus (flaviridae)
77
What is the outer covering of the Ebola virus?
Envelope. Therefore there are glycoproteins.
Nucleocapsids with VP24, VP35, VP30 as nucleoproteins
Released at LE
78
Through what tract is reovirus transmitted through?
The upper alimentary tract
79
Paramyxoviridae
(-) ssRNA like in Ebola
80
What was the first transmission of SIV/HIV to humans thought to have been?
subtype M
81
What is the outer covering of HIV like?
1,500 proteins
enveloped, has glycoproteins gp120, gp41
conical nucleocapsid, p24
82
Tobacco mosaic virus
Helical symmetry, rod-shaped
83
Hepatitis A
A part of the picornaviridae class
90s in early february in Puglia, Italy. Every february 40% of poeple got sick with liver damage and jaundice. Ate raw oysters annually on NYE. Fishermen excreted the virus into the water in Puglia. Oysters became infected.
84
Orthmyoxoviridae
(-) ssRNA (like ebola)
85
What are cathepsins involved in?
Release of non-enveloped viruses at the late endosome
cysteine proteases
86
How frequently is HIV transmitted during a coital act?
1/1000 times
87
Heterosexual black couples in Africa?
C
88
Outer covering of WNV?
Envelope
| (also nucleocapsid and (+)ssRNA genome)
89
How does integrase works?
Removes two terminal 3' nucleotides on either strand of dsDNA (proviral). 3' OHs are integrated into a break in the host genome
90
What is the Curvularia thermotolerance virus?
Dichanthelium lagunosinum
91
What is the pH of the skin?
5.5
92
Lentivirus
A subtype of retroviridae HIV, HIV-1 and HIV-2
93
VP24, VP30, VP35
Found in the ebola nucleocapsid, helical symmetry
94
95
What is an icosahedron?
A solid with 20 faces
