virus replication Flashcards
(26 cards)
what is a virus
intracelular parasite comprising of dna or rna
what surrounds the genetic material
protein coat or an envelope
what do viruses require for replication
host cell metabolic
what are the two phases of virus
virion and infected cell
What are the general features of a virus
naked or enveloped
icosahedral or helical
what are the 5 rules of DNA viruses
are HHAPPY
are double stranded
have linear genomes
replicate in the nucleus
are icosahedral
what does HHAPPy stand for
hepadna, herpes, adeno, pox, parvo, papilloma , polyoma
which DNA viruses do no have linear genomes
papilloma, polyoma, and hepadna
General rules of RNA viruses
for + stranded rna viruses
for - stranded rna viruses
all replicate in the cytoplasm
rna-dependent rna polymerase is made from viral genome
RdRp is carried by viral particle into the cell
step one of viral replication
attachment to receptor on cell surface
step 2 of viral replication
entry through endocytosis or fusion of the viral envelope to the host cell membrane
step 3 of viral replication `
un coating or release of viral nucleic acid
step 4 of viral replication
replication
what are the 3 parts to step 4 of replication
- synthesis of viral protein
- replication of viral genome
- synthesis of capsid and other structural protein
step 5 of viral replication
assembly new viral particles
step 6 of viral replication
release from host cell by lysis or budding
what is tropism
host cell proteins dictate species/tissue/cell tropism of the virus
what can alter virus tropism
alterations in the affinity of the virus for a particular host cell receptor
positive sense rna genome is
directly translated into proteins
negative sense rna genome
has to be transcribed into rna by viral RdRp before translation of viral proteins
replication happeneds where
in cytoplasm except influenza and HIV
what is the exception to replication in the nucleus
poxviruses
for influenza virus envelope is acquired in
the plasma membrane
For herpes envelope is in
the Golgi