Virus Life Cycle Flashcards
What structures interact in virus recognition?
ECM (tissues) and virion
What structures interact in virus attachment?
virion and specific cellular receptor
What is the viral host range?
preferred species
What is the viral tissue tropism?
preferred cell type
What makes a cell susceptible to viral infection?
virus can enter
What makes a cell permissive to viral infection?
virus can replicate and synthesize
What happens in a viral abortive infection?
viral replication is incomplete
what are the three mechanisms of viral penetration?
receptor-mediated endocytosis
pinicytosis
phagocytosis
what are the two ways a virus can enter a cell?
penetration
fusion
What happens in viral fusion?
virion envelope fuses with plasma membrane, leaves parts of virion behind
what is released in viral uncoating? what does this mark the beginning of?
genome is released
beginning of eclipse phase
Besides direct penetration, what are three mechanisms/locations of viral entry and uncoating?
at plasma membrane
endocytosis
at nuclear pore
Do viruses made mRNA?
yes - all do
Are the transcriptions factors which regulate mRNA synthesis viral or host?
Both
Where does the machinery to translate mRNA into protein come from? What molecules are used?
Host
ribosome, tRNA, amino acids
During virion assembly, what viral proteins interact with the newly made genomes?
capsid proteins
During virion assembly, what do membrane proteins traffic through?
secretory pathway
During virion assembly, what do cystolic proteins accumulate next to?
membrane
What marks the end of a viral eclipse phase?
virion assembly
When are the steps of virion assembly?
capsid proteins form empty shell
viral DNA inserted into capsids
which shapes of capsids self-assemble?
icosahedral
helical
what kind of capsid is made of a genome coated with nucleoproteins?
complex capsid
From where do enveloped viruses acquire membranes?
host ER, golgi, or PM
What must happen before capsid assembly? Can this happen at the same time as envelopment?
all virion components assemble at site of capsid assembly
cannot happen at the same time as envelopment
How are virions released from the cell?
lysis
budding
exocytosis
which form of virion release is active transport?
exocytosis
How is the eclipse phase of a single-step virus growth curve characterized?
no virus it recovered - replication and assembly
What is a viral burst size?
number of infectious viral progeny from a single round of replication
What is a PFU? What does it measure?
Plaque Forming Unit
measures infectious virions
