Flashcards in Introduction to viruses Deck (27)
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1
What size are viruses
Small: 20 – 400 nm diameter
2
What is the 3 structure of viruses
Icosahedral: 20 faces equilateral triangle
Helical: protein binds round DNA/RNA in a helical fashion
Complex: neither
3
What does it mean that viruses are Obligate intracellular pathogens
can only replicate inside host
4
What is the order of taxonomy
Order
Family
genus
species
(oh my freaking god sarah)
5
Viral families classified by
shape/symmetry
envelope
genetic structure
mode of replication
6
What do they spiral infections do for the virus
provide natural immunity
7
What is a virus composed of
nucleic acid
Lipid envelope
Protein capsid
Virion associated polymerase
8
Process of viral replication
attaches, uncoats RNA, replication of virus RNA in MRNA synthesis, virus protein synthesised, budding and related on the surface
9
What are the different viral transmissions
Blood borne
Sexual
Droplet
Airborne
Close contact
Vector borne
Zoonotic (Animals)
10
What isa droplet transmission; example
Large particle with small projection; Influenza,
11
What is a airborne transmission; example
Particle transferred in the air environment; Measels, chicken pox
12
What does coinfection of human and animal or bird lead to
may lead to recombination and generation of a new strain
13
Novel virus
Virus that has not be seen before
14
What does a clearance of viral infection mean
you don't get any immunity e.g. influenza
15
What immunity does Measels have
Long term immunity
16
What infection is HIV, hepatitis B, hepatitis C
Chronic infection
17
What is viral latency
Virus lies dormant, then something triggers the virus
eg. immune system supresors/ stress etc.
18
What is viral transformation
long term viral infection that alters gene expression e.g. cancer
19
Example of viral infections that cause transformation i.e. cancer
Epstein-Barr Virus --- glandular fever
Human Papillomavirus --- causes cervical cancer
Hepatitis B/C : hepatocellular carcinoma
Human T-cell Lymphotropic Virus: Adult T-cell leukaemia/lymphoma
20
What viruses are latent
Herpes Simplex Virus (coldsore)
Varicella Zoster Virusm (chicken pox)
21
How does viral infections cause cancer
Modulate cell cycle control
Modulating apotosis
Promote oxidation
(some persistent viral infections can cause persistent inflammatory processes which lead to cancer)
22
How do you detect a whole virus organism
electron microscopy or grown in cell culture
23
How do you detect part of virus organism (antigen, nucleic acid)
antigen detection detected from viruses immune response
DNA/RNA replication from PCR
Amplification of region target organism genome
24
What is antiviral therapy
treating viruses by binding to cell and preventing viral replication
25
Antivirals are used for
Prophyaxis - prevent disease
Pre-emptive therapy - treat before symptoms
Overt disease
Suppressive therapy - keep viral replication below the rate that causes tissue damage in an asymptomatic infected patient
26
How do you prevent viral infection
immunisation - vaccination
Antenatal screening
27
