Taxonomy virus Flashcards
(39 cards)
virus are grouped in ?
families
virus are given what to name them?
- Genus name
- Species name
classification of virus is based on what ?
- Nature of the host
- Type of disease caused
- Life cycle
- Naked or enveloped
- Type of nucleic acids and strandedness
What’s the baltimore classficiation scheme?
the type of genome , kind of genome will dictate the replication mechanism
There are two type of RNA genomes
- Plus configuration
- Minus configuration
What’s the plus configuration of RNA genomes?
It’s the same strand of dna and can be translated directly
What’s the minus configuration of RNA genomes?
complementary in base sequence to viral mRNA (needs to be transcribed into plus strand before it can be translated
Life cycle of viruses ,first step?
Adsorption
What’s adsorption ?
attachment - virus - specific receptors- surface of the cell.
plants viruses are usually introduced into the host by ?
insect vectors or following mechanical damage
life cycle of viruses,second step?
Penetration,virus genome enters the cell
in envelopped and naked viruses what enters the cell ?
complete virion may enter the cell
In envelopped virus, the envelope may?
be left at the cell surface such that only the nucleopsid enters the cell
In naked viruses?
the capsid may be left at the surface(everything left at the surface)
Uncoating?
removal of the envelope and/or the capsid by host enzymes,sometimes within lysosomes(in eukaryotes)
direct penetration?
naked virus,everything is left at the surface
In membrane fusion ? (enveloped viruses)
the envelope is left at surface
Who does endocytosis to enter
Most enveloped viruses of eukaryotes (they use viropexis)
What’s viropexis?
Everything gets in (in a second envelope)
What happens with the second envelope that goes in ?
viruses are then delivered to lysosomes which degrade the capsid and the nucleic acid is release into the cytoplasm
Life cycle, third step?
replication of the nucleic acid transcription and protein synthesis
life cycle,fourth step?
Maturation, assembly of virus components,nucleic acid,nucleocapsid and acessory proteins to form new virions
How quick happens the assembly?
spontaneous (occurs by itself)
LIfe cycle, fifth step?
release,matura virions exit the host cell by means of budding or by causin lysis of the cell
