Intro to virology Flashcards
What is a virus
Obligate intracellular parasite
What does a viral particle consist of
nucleic acid
protein shell
lipid envelope (sometimes)
How do viruses replicate
virus genome directs the synthesis of virus proteins/progeny genome using its host cell
What are viral particles assembled from
virus components produced by the host cell
What do viruses lack which mean they cannot produce their own proteins
ribosomes
ATP
What diseases are caused by icosahedral viruses
adenovirus
papillomavirus
rotavirus
Why do viruses that cause different disease all have similar shapes
due to simple structure
What diseases are caused by ssRNA viruses
influenza
ebola
parainfluenza
What is the function of the protein capsid
protects the genome from the environment
delivers genome to cell
What are the stages in the viral growth cycle
attachment
entry
uncaring
synthesis of viral components
assembly and release
What can occur to the viral genome once inside the host cell
gene expression
genome replication
What is the outcome of viral gene expression
mature proteins
How do enveloped viruses acquire their envelopes
budding
Where are the main viral entries into host
Respiratory tract
Gastro-intestinal tract
urogenitary treat
blood (vertical or horizontal)
What are the mechanisms of viral spread
localised (no spread)
neural spread
hematogenous blood
What viral factors can limit the host and viral spreading
cell lysis (immune response)
alteration of host cell cycle
What host factors can limit the spread of a virus or cause the death of a host
apoptosis
lysis
inflammation
How can the adaptive immune system respond to infection
neutralising antibodies
cytotoxic T cells
How are viral infections diagnosed
PCR
Antigens
Antibodies
Why do anti-viral drugs have to be unique
to ensure they only target the virus and not the host
target components only virus has
What potential components could anti-viral drugs target?
viral nucleic acid polymerases
viral enzymes involved in genes/proteins
Which virus affects the human respiratory and GI tract
adenovirus
Which virus causes STD
papillomavirus (HPV)
