1
Q
What are capsids
A
the protective protein coat of a virus that is protecting the genome
2
Q
what are the types of genomes a virus can have
A
Can be single, stranded or double stranded DNA.
can be single, stranded or double stranded RNA.
It can be positive or negative sense RNA.
3
Q
all viruses have
A
capsids
4
Q
what is viral envelope
A
the phospholipid bilayer that some viruses have
5
Q
briefly describe the viral replication cycle
A
the virus getting in, making more of its genome, making more of its proteins, making a new particle and getting out.
6
Q
what is the feature that SOME viruses have
A
viral envelope
7
Q
what are the three DNA viruses
A
Papillomaviridae, Herpesviridae, Poxviridae
8
Q
What is the name of the icosahedral non envelope virus that has a double stranded DNA ciruclar genome
A
Papilloma virus
9
Q
the virus the causes warts and cervical cancer
A
Papilloma virus
10
Q
Icosahedral enveloped virus that has double straded linear DNA
A
Herpes virus
11
Q
HSV-1 OR HHV-1 causes
A
cold sores
12
Q
HSV-2 causes
A
the sexual transmitted disease that causes genital herpes
13
Q
Varicella-zoster virus causes
A
chickenpox and shingles
14
Q
Epstein–Barr virus is also known as
A
kissing disease
15
Q
herpes and pox virus are
A
DNA viruses that are enveloped
16
Q
the name of the virus that causes smallpox
A
poxviridae
17
Q
complex vs icosahedral describes the shape of the
A
viral capsid
18
Q
what is herpesviridae
A
icosahedral envoloped double stranded linear DNA
19
Q
What is poxviridae
A
Complex enveloped double stranded linear DNA
20
Q
the viruses under the herpesvirus family
A
varicella zoster virus (HHV-3)
Epstein-Barr virus (HHV-4)
Hepres simplex viruses (HHV-1 and HHV-2)
21
Q
refers to a collection of species that a virus can infect
A
host range
22
Q
viruses that only infect one species is known as
A
host tropism
23
Q
example of host tropism
A
measles !
24
Q
Viruses that infect both animals and humans are called
A
zoonotic virus
25
tropism basically means
preference
26
refers to tissue or cell specificity due to viral surface factors
tropism
27
Broad tropsim
viruses that can infect a wide range of host cells or
tissues
28
narrow tropism
viruses that can infect only one type of host cell or tissue
29
Ebola is an example of
Broad tropism- Ebola attaches to a lot of different molecules on the surface of cells. This makes it very deadly for us. It can attach to sugars. It can attach to lipids. The first thing it gets into is macrophages. But then it gets into your liver cells your kidney cells. It gets into the epithelial layer and that's where you get bleeding out.
30
HIV is an example of
narrow tropism--> infects CD4 T -cells and macrophages
31
define acute infection
viruses
infect a host cell and new
virions are made
immediately
32
Examples of chronic infections
EBV and HIV
33
purpose of plaque assay
to get an idea of how much virus is in a certain sample
34
single, infectious virus particle
Have an exterior protective protein capsid
Contain genetic material (DNA or RNA)
virion
35
accounts for the bulk of a virion's mass
capsid
36
made of capsomere subunits
capsid
37
shaped like a soccer ball
icosahedral capsid
38
are held together via protein-protein interaction, theres nothing covalent in these
this is how the capsid protein shells of a virus is held together
39
viruses that infect bacteria and kill them
bacteriophages
40
Arise from budding off the host cell (take a portion of
the cell membrane with them)
they keep the cell alive usually in this process
enveloped viruses
41
Arise from lysing (bursting) the host cell
nonenveloped viruses
42
lyse host cells, therefore they are always naked non-enveloped
bacteriophages
43
function of viral spikes
help viruses attach and gain entry to host cells
44
what are viral spikes
these are transmembrane proteins that protude from the viral capsid or envelope
45
what are the two spike proteins that Influenza A has
Hemagglutinin (HA)
Neuraminidase (NA)
46
How does HA function
HA is the spike protein that will attach to a cell surface receptor and help the virus get into the cell by membrane fusion
very important protein as it is very immunogenic (elicits an immune response)
47
How does NA function
after the flu virus has replicated itself inside of a host cell, the virus wants to get out to infect something else but it wont be able to leave the cell if the receptor on the surface of the target cell is there due to tropism
so in the case of influenza, neuraminidase cleaves the receptor off to allow the particle to fully leave the cell
48
the viral genes encode
the enzymes needed for replication, and structural proteins (the capsid proteins)
49
influenza RNA gene, is it single or segmented sections
segmented
50
what does dsDNA virus need to do before transcription and translation
nothing! the viral dna is transcribed using RNAP into mRNA and that is then translated
51
what does ssDNA virus need to do before transcription and translation
converted to a double-stranded form before transcription
52
negative sense RNA is transcribed into functional mRNA via
RNA-dependent RNA polymerases (RdRPs)
53
positive sense RNA meaning
it is a viral genomic rna, but more specifically it is the genome of RNA viruses that also functions directly as messenger RNA inside the host cell
our ribosomes will only work on positive sense RNA
our mRNA is positive sense RNA, meaning that its nucleotide sequence is in a readable way to make a protein
54
why do RNA genomes mutate more than DNA
because RDRPs are error prone
55
RDRPs
the enzyme RNA viruses use to copy their RNA genome
56
vaccines are
Genetic changes that limit infectivity lead to attenuated strains.
57
influenza vaccines are made by
passage of the influenza virus through a chicken eggs and that RDRP makes errors and changes it enough that we will still make great antibodies to it. It will run a great immune response in us, but wont make us sick. attenuated virus
58
antigenic shift
big genetic reassortment/change of the virus
eg. if a cell has two virus genomes, thos can mix up and now we have mixed viruses which creats a new highly virulent human strain
59
antigenic drift
tiny changes to the virus genome
for eg. the influenca genome changes a little every year due to RDRP being error prone and making mistakes during replication
60
anitgenic _____ sets the stage for a pandemic
shift
61
Flaviviruses examples
Hepatitis C virus
West Nile virus
Dengue fever virus
62
ICOSOHEDRAL enveloped single stranded RNA non segmented
flavivirus and retrovirus
63
helical enveloped single stranded non segmented RNA
COVID
64
the only segmented one we learned was
influenza
65
DEFINE TROPISM
The transmembrane proteins on the virus capsid (spiked) being attracted to a receptor on a cell
66
poliovirus size
30 nm
67
rhinovirus size
30 nm
68
HIV size
120 nm
69
bacteriophage size
225 nm
70
ebola virus
970 nm
71
pandoravirus
1000 nm
72
pithovirus
1500 nm
73
viral genes code for stuctural proteins (spike, capsid, envelope proteins) which form new virions and these virions
manipulate your cells
Shut down host protein synthesis
Block interferon responses
Disrupt immune signaling
Trigger inflammation
73
e.coli bacterium size
2000 nm
74
how do non-enveloped viruses attach
through capsid proteins. there will be a protein in the capsid that will attach to that virus's receptor
75
how do enveloped viruses attach
the virus protein that will attach to its receptor will be the transmembrane protein embedded in the phospholipid bilayer
76
how do nonenveloped virus enter the host cell
endocytosis
77
how do enveloped virus enter host cells
fusion
78
Uncoating
Capsid is digested by enzymes in the endocytic vesicle or cytoplasm or nucleus
79
assembly
new virions
79
replication (synthesis)
Genome is replicated and
viral proteins are made
80
how are enveloped viruses released from the cell
via budding
81
how are non enveloped viruses released
they rupture the host cell during release
81
replicating all the time at low level
persistent infection
82
viruses infect a host cell, replication is quick, and virions are made immediately
acute infections
83
what are the 4 conventions that virus names are based off of
type of nucleic acid (dna or rna)
genome architecture (eg. ssDNA or ssRNA)
capsid symmetry/ shape
presence of envelope
84
integrated viral genome into the host dna
provirus
85
what are endogenous retroviruses
HIV is an example of this, it integrates into our dna and its there permenantly, so it can always make virus from that intergrated genome thats in our cells
Microbiology
flashcards
Decks in class (11)
# Cards
-
CHAPTER 9- Principles of Infectious Disease and Epidemiology31
-
VIRUSES88
-
metabolism34
-
microbial growth and decontaimination63
-
Chpt 10 Host-Microbe Interactions and Pathogenesis48
-
chapter 11 innate immunity87
-
CHPT 1350
-
nervous system and infections1
-
skin and eye infections70
-
chpt 15 antimicrobials13
-
CHPT 16103
