Viral Replicatiion Flashcards
where is viral replication studied
in vitro
what is an eclipse time period
the time after the virus has penetrated the cell but cannot be observed for hours until the first progeny of virions become visible again
true or false
the eclipse time is related to the incubation time of the virus
false – it is unrelated
true or false
eclipse time is important time where antiviral drugs can interfere with viral replication
true
what is a susceptible cell line
virus can infect but not complete the replication cycle
what is the permissive cell lines
virus can infect and complete the cycle
how would you describe the ‘growth curve’ of a virus
exponential growth
what type of virus can have attachment but no replication
susceptible cell lines
what type of virus can have attachment and replication
permissive cell lines
why is having cell/target-specific drugs important
can eliminate the chances for toxicity
what occurs during ‘attachment’ in viral replication
receptors on the viral envelope or capsid become connected to complementary receptors and coreceptors on the cell membrane expressed in susceptible cells
what are ways of viral penetration
- membrane fusion
-endocytosis
-genetic injection
what are 2 types of uncoating
complete
incomplete
where does the virus ‘dump’ or release the DNA
in the nucleus or in the cytoplasm depending on the virus
what cell component is used to move the virus in the cell
chaperons
what 3 steps can become ‘switched up’ in replication
transcription
translation
replication
what do DNA viruses that replicate in the nucleus use to replicate / produce mRNA
cellular DNA-dependent RNA polymerase
what type of virus is an exception to replicating using cellular DNA dependent RNA polymerase
poxviruses
- replicate in cytoplasm and have thier own DNA-dependent RNA polymerase
which type of virus can directly bind to ribosomes and start translating either partially or fully
+ RNA virus single stranded
what type of virus must carry their own polymerase enzyme inside their nucleocapsid
- sense RNA virsuses
what is used for cellular replication (DNA virus)
DNA dependent DNA polymerase (DNA synthesis)
DNA dependent RNA polymerase (mRNA synthesis)
what is used for viral replication (RNA virus)
RNA dependent DNA polymerase (retrotranscriptase)
RNA dependent RNA polymerase (RNA viruses)
DNA dependent RNA polymerase (DNA virsuses that replicate in the cytoplasm)
why do we care about viral mechanism of replication
drug mechanism choices
what can be added after transcription / translation
cap
poly A tail
where do naked viruses usually accumulate
nucleus
cytoplasm
how do naked viruses usually exit the cell
lysising
how do enveloped viruses exit the cell
budding
exocytosis
what can be a possible outcome of lysing of cells due to naked virus exit
inflammation
how does retrovirus replication occur
retrotranscriptase enzyme with RNA dependent DNA polymerase capability
what enzyme is unique to retroviruses
reverse transcriptase enzyme
what is the purpose of long terminal repeats
-allows viral genome to integrate to host genome
-acts as a strong promotor
what is the result of an LTR becoming a strong promotor
it is responsible for asking for more replication - could be used to explain rapid cell growth / cancers
