Virus, Viroids, And Prions Flashcards
1
Q
Up to How many permanent infectious viruses does a healthy human harbor
A
Up to 10
2
Q
It is the viral portion of the microbiome
A
Human virome
3
Q
Is found in the same sites as the majority of bacterial microbiome
A
Human virome
4
Q
What are the sites where human virome is found
A
Mouth, nose, skin, vagina and intestines
5
Q
Human virome include ______ and ______ viruses
A
Persistent and latent
6
Q
Integrated into human chromosomes makes up about 8% of the human pathogenic bacteria
A
Retrovirus genetic material
7
Q
Retrovirus genetic material makes up how many percent of the human genome
A
8%
8
Q
The vast majority of human virome consists of what; these are viruses that infect bacteria
A
Bacteriophages or phages
9
Q
These affects human health and dse bu controlling growth of normal and pathogenic bacteria
A
Bacteriophages
10
Q
2 kinds of bacteriophages
A
Kill the winner
Kill the competitor
11
Q
Kill the winner or kill the competitor:
Strategy involves bacteriophages targeting and killing dominant bacterial colonizers in the body. This action helps prevent colonization by pathogens, as the bacteriophages benefit from having a host for reproduction.
A
Kill the winner
12
Q
Kill the winner or kill the competitor:
By eliminating dominant bacterial colonizers, the __________ strategy prevents pathogen colonization, thus aiding in the maintenance of a healthy microbiome.
A
Kill the winner
13
Q
Kill the winner or kill the competitor:
strategy involves bacteriophages protecting the bacterial microbiome from invasion by other bacteria vying to gain a foothold in the area. This helps maintain the balance of the microbiome.
A
Kill the competitor
14
Q
Kill the winner or kill the competitor:
In the intestines, certain bacteria release lytic bacteriophages when competing enterococci are present. This action eliminates the competition and preserves the stability of the microbiome.
A
Kill the competitor
15
Q
In kill the winner, what do bacteriophages kill
A
Colonizers
16
Q
In an example of kill the competitor, im the intestines, ________ bacteria release ______ bacteriophages, from ____, when competing _________ are present - thus killing the competition
A
Enterococcus
Lytic
Prophages
Enterococci
17
Q
The virus remains in the host cell for long periods without producing infection
A
Latent viral infections
18
Q
Examples of latent viral infections
A
Cold sores and shingles
19
Q
Dse processes that occur over a long period and generally fatal
A
Persistent viral infections
20
Q
Persistent viral infections are caused by what kind of viruses; these viruses accumulate overe a long period of time
A
Conventional viruses
21
Q
Measle virus can be responsible for a rare form of encephalitis called what
A
Subacute sclerosing panecephalitis (SSPE)
22
Q
May be regarded as exceptional complex aggregations of non living chemics or as exceptionally sinple living microbes
A
Viruses
23
Q
Viruses contain a single type of _______ ______ (_______ or ______) and a ______ coat, sometimes enclosed in an envelope composed of _____,_____, and ______
A
Nucleic acid (DNA or RNA)
Protein
Lipids, protein, and carbohydrates
24
Q
Viruses are _________ _______ _________; they muliply by using the host cell’s synthesizing machinery to cause the synthesis of specialized elements that can transfer viral nucleic acid to other cells
A
Obligatory intracellular parasites
25
The spectrum of host cells in which a virus can multiply
Host range
26
These aee viruses that infect invertebrates, vertebrates, plants, protists, fungi, and bacteria
Host range
27
Host range is determined by ______ _____ _____ on the host's ______ _____ and the availability of _____ _______ _____
Specific attachment sites
Cell's surface
Host cellular factors
28
Viral size is ascertained by what
Electron microscopy
29
Viruses range from what length
20-1000 nm
30
A viral structure that is complete, fully developed viral particle composed of nucleic acid surrounded by a protein coat oitside of a host cell
Virion
31
In viruses, nucleic acid may be ______ - or _____ - stranded, ______ or ______, or _____ into several separate molecules
Single- or double- stranded
Linear or circular
Divided
32
The range of the proportion of nucleic acid in relation to protein in viruses
1% - 50%
33
Protein coat surrounding the nucleic acid of a virus
Capsid
34
Subunits that composes a capsid, ehich can be single type of protein or several types
Capsomeres
35
Capsids are enclosed by what; it consists of lipids, proteins, and carbohydrates
Envelopes
36
Carbohydrates-protein complexes that covers envelopes
Spikes
37
Spikes are what kind of complex
Carbohydrates-protein complexes
38
Give a virus thatvis nonenveloped
Polyherdral (icosahedral) virus
39
Viruses that are hallow cylinders surrounding the nucleic acid
Helical viruses
40
Viruses that are many-sided
Polyhedral viruses
41
Example of an enveloped helical virus
Influenza virus A2
42
A helical virus, also called filovirus, showing helical rodlike shape
Ebola virus
43
Viruses that are coveredd with envelope and are roughly spheric but highly pleomorphic
Enveloped viruses
44
Enveloped viruses are highly ____
Pleomorphic
45
Viruses with complex structures
Complex viruses
46
An example fo complex viruses:
Many bacteriophages have ______ _____ with a _______ tail attached
Polyherdral capsid
Helical
47
Example of a complex virus (bacteriophage)
T-even bacteriophage
48
A virus that causes smallpox
Variola virus
49
Variola virus is a species in the genus ___________
Orthopoxvirus
50
What don't viruses contain for energy production or protein synthesis
Enzymes
51
For a virus to multiply, it must ______ a host cell and direct the host's ______ _________ to produce ______ ________ and components
Invade
Metabolic machinery
Viral enzymes
52
During this cycle, a phage causes the lysis and death of a host cell
Lytic cycle
53
Some viruses can eitrher cause _____ or have their ___ incorporated as a ________ into the ______ of the host cell. The latter situation is called ________
Lysis
DNA
Prophage
DNA
Lysogeny
54
In ________, phage lysozyme opens a portion of the bacterial cell wall, the tail sheath contracts to force the tail core through the cell wall, and phage DNA enterd bacterial cell. Capsid remains outside
Penetration
55
Capsid is also called as the what
Head
56
In penetration what opens a portion of the bacyerial cell wall
Phage lysozyme
57
In penetration, what contracts to force the tsil core through the cell wall
Tail sheath
58
In penetration what eneterd the becterial cell
Phage DNA
59
In penetration what remains outside
Capsid
60
In _______, transcription of phage DNA produced mRNA coding for proteins necessary for phage multiplication. Phage DNA is replicated, and capsid proteins are produced
Biosynthesis
61
In biosynthesis, what does the phages DNA undergoes to produce mRNA coding for proteins
Transcription
62
In biosynthesis , transcription of phage DNA produces what?
mRNA coding
63
In biosynthesis, what is necessary for phage multiplication
mRNA
64
During this period, separate phage DNA and protien can be found
Eclipse period
65
During _______, phage DNA and capsids are assembled into complete viruses
Maturation
66
5 steps in multiplication of bacteriophages
1. Attachment
2. Penetration
3. Biosynthesis
4. Maturation
5. Release
67
A process in multiplication of bacteriophages where the ohage attaches to the host cell
Attachment
68
A process in multiplication of bacteriophages where the phage penetrates host cell and inject its DNA
Penetration
69
A process in multiplication of bacteriophages where the ohage DNA directs synthesis of viral components by the host cell
Biosynthesis
70
A process in multiplication of bacteriophages where the viral components are assembled into virions
Maturation
71
A process in multiplication of bacteriophages where host cell lyses, and new virions are released
Release
72
Parts of a phage
Capsid (head)
DNA
Tail:
-Sheath
-Tail fiber
-Baseplate
-Pin
73
During _____, phage lysozyme breaks down the bacterial cell wall, and the new phages are released
Release
74
During release, what do phage lysozyme break down
Bacterial cell wall
75
During this cycle, prophage genes are regulated by repressor coded for by the prophages. The prophage is replicated each time cell divides
Lysogenic cycle
76
During lysogenic cycle, what regulates prophage genes
Repressor coded
77
What happens to prophage during lysogenic cycle each time the cell divides
It replicates
78
What causes lysogenic cells become immune to reinfection with the dame phage and may undergo phage conversion
Lysogeny
79
Because of lysogeny, _______ cells become immune to _______ with the same phage and may undergo ______ ______
Lysogenic
Reinfection
Phage conversion
80
In lysogenic cycle, after the phage attaches to host cell and inject DNA, and phage DNA circularizes and enterd lysogenic cycle, what happens then? (3 processes)
1. Phage DNA integrates within the bacterial chromosome by recombination becoming a prophage
2. Lysogenic bacterium reproduces normally (many cell division)
3. Occasionally, the prophage may exise from the bacteri chromosomes chromosome by another recombination event initiating lytic cycle
81
In lysogenic cycle, the phage DNA integrates within the bacterial chromosome by _____ and becoming ______
Recombination
Prophage
82
A phage that can transfer bacterial genes from one cell to another through transduction
Lysogenic phage
83
Throught this process, a lysogenic phage csn transfer bacterial genes from one cell to another
Transduction
84
A kind of transduction where any genes can be transferred
Generalized transduction
85
A kind of transduction where specific genes can be transferred
Specialized transduction
86
Processes of a specialized transduction (6)
1. Prophage exist in galactose-using host (containing gal gene
2. Phage genome exercise carrying with it the adjacent gal gene frkm the host
3. Phage matures and cell lyses, releasing phage carrying gal gene
4. Phage infects a cell that cannot utilize galactose (lack gal gene)
5. Along with the prophage, the bacterial gal gene becomes integrated into the new host's DNA
6. Lysogenic cell can now metabolize galactose
87
Ina specialized transduction, prophage exist in what kind of host
Galactose-using host
88
What do the galactose-using host contain
Gal genes
89
True of false:
In specialized transduction, when a prophage is excised from its host chromosome, it caan take with it a bit of adjacent DNA from the bacterial chromosome
True
90
In the multiplication of animal viruses, what part of the host cell does it attached to
Plasma membrane
91
How does the entry of animal viruses occur
By receptor-mediated endocytosis or Fusion
92
What fuses when the virus enter host cell during fussion
Viral envelope and cell membrane
93
Animal viruses are uncoated by what kind of enzymes
Viral or host cell enzymes
94
During animal virus multiplication, DNA of most DNA virus is released into the ____ of the host cell
nucleus
95
During the multiplication of animal viruses, _______ of DNA and _______ produce viral DNA and, later capsid proteins
Transcription
Translation
96
During the multiplication of animal viruses, what does translation produce
Viral DNA and, later, capsid proteins
97
During the multiplication of animal viruses, these are synthesized in the cytoplasm of the host cell
Capsid proteins
98
Where are capsid proteins synthesized
Cytoplasm of the host cell
99
Where does the multiplication of RNA viruses occur
Cytoplasm of the host cell
100
During the multiplication of animal RNA viruses, what synthesizes a double-stranded RNA
RNA-dependent RNA polymerase
101
What does the RNA-dependent RNA polymerase synthesize
Double-stranded RNA
102
What happens after assembly in the multiplication of animal viruses
Virese are released
103
Its one method of release (and envelope formation) during multiplication of animal viruses
Budding
104
In nonenveloped viruses, viruses are released through ______ in the host cell membrane
Raptures
105
Differentiate the difference between the attachment of bacteriophages and animaal viruses
Bacteriophages:
Tail fibers attach to cell wall proteins
Animal viruses:
Attachment sites are plasma membrane proteins and glycoproteins
106
Differentiate the entry between the bacteriophages and animal viruses
Bacteriophages:
Viral DNA is injected into host cell
Animal viruses:
Capsid enters by receptor mediated endocytosis or fusion
107
Differentiate the uncoating between bacteriophages and animal viruses
Bacteriophages:
Uncoating is not required
Animal viruses:
Enzymatic removal of capsid proteins
108
Where does biosynthesis occur in bacteriophages and animal virusesa
Bacteriophages:
Cytoplasm
Animal viruses:
Nucleus (DNA viruses) or Cytoplasm (RNA viruses)
109
Differentiate thew chronic infection between bacteriophages and animal viruses
Bacteriophages:
Lysogeny
Animal viruses:
Latency; slow viral infections; cancer
110
What happens during the release in bacteriophages and in animal viruses
Bacteriophages:
Host cell is lysed
Animal viruses:
Enveloped viruses bud out; non enveloped viruses rupture plasma membrane
111
When was the earliest relationship between cancer and viruses demonstrated
Early 1900s
112
Cancer and viruses relationship was demonstrated when ______ _______ and _______ ________ where transfered to healthy animals by ___________ ______
Chicken leukemia
Chicken sarcoma
Cell-free filtrates
113
In the transformation of normal celld into tunor cells, when oncogenes are activated, it transforms _____ cells into ______ cells
Normal cells
Cancerous cells
114
When activated, it transforms nirmal crlls into cancerous cells
Oncogenes
115
Viruses trhat are capable of producing tumors
Oncogenic viruses
116
What kind if viruses are oncogenic
Some DNA viruses and retroviruses
117
What part of the oncogenic viruses becomes integrated into the host cell's DNA
Genetic material
118
During rhe transformation of normal cells into tumor cells, transformed cells contain ________________ ______ (___), exhibit _______ _______, and can produce _______ when injected into _______ animals
Virus-specific antigens
(TSTA)
Chromosome abnormalities
Tumors
Susceptible
119
Where are DNA Oncogenic viruses found (5)
1. Adenoviridae
2. Herpesviridae
3. Poxviridae
4. Papovaviridae
5. Hepadnaviridae
120
What kind if oncogenic virus has the ability to produce tuinors that are related tk the presence of reverse transcriptase
RNA oncogenic viruses
121
RNA oncogenic virsues has the ability to produce _____ is related to the presence of _____ __________
Tumors
Reverse transcriptase
122
RNA oncogenic virsues:
The _____ synthesized from the ____ _____ becomes incorporated as _______ into the host cell's DNA
DNA
viral RNA
Provirus
123
Viruses that enter plant hosts throught wounds or with invasivr parasitrs, such as insects; some also multiply in insect (vector) cells
Plant viruses
124
How do plant viruses enter a plant host
Though wounds or invasive parasites (s.a. insects)
125
How does a plant viruse multiply with the usaew of insects
Through insect (vector) cells
126
Infectious pieces of RNA that causes some plant dse
Viroids
127
Viroids enclosed in a protein coat
Virusoids
128
Are infectious proteins first discovered in 1980s
Prions
129
When were prions first discovered
1980s
130
Prion dse involves the degeneration of _____ ______
Brain tissue
131
Prion dse involve the ______ of brain tissue
Degeneration
132
A dse that result from an altered protein
Prion dses
133
What causes prion dse (2)
Mutatiom in the normal gene for PrPc (cellular prion protein)
Or
Contact with an altered protein (PrP^Sc for scrapie protein)
134
What is PrP^c
Cellular prion protein
135
What is the altered protein for scrapie protein
PrP^Sc
136
Prions include __ animal neurological dses called _______ ________ ________ bcs. large _____ develope in the brain
9
Transmissible spongiform encephalopathies
Vacuoles
137
Prions that are human dses (4
Kuru
Creutzfeldt-Jakob dse (CJD)
Gerstmann-Sträussler-Scheinker syndrome
Fatal familia insomnia
138
What kind of prion protein enters a cell and chanhes a normal prion protein PrPc to PrPSc
Abnormal prior protein (PrPSc)
139
What does a PrPSc changes PrPc into?
PrPSc
140
How is the accumulation of PrPSc in the cell and on thr crll surface
1. Abnormal prior protein (PrPSc) enterd cell
2. It chanhes normal prion protein (PrPc) intro PrPSc
3. PrPSc changed another normal PrPc
4. Resulting in an accumulation of the abnormal PrPSc in the cell and on the cell surface
