Middleton- virus structure, classes Flashcards
_____ are smaller than bacteria, fungus, and other microorganisms
viruses
Viruses need what to replicate?
a host
T/F: viruses are autopoeitic
false
what is the Cellular origin theory of viruses?
Proposes that viruses were once cellular components but over time they evolved separately
what is the Autopoietic origin theory of viruses?
Proposes that viruses, once autopoietic entities, became dependent on cells for replication.
which characteristics are used to classify viruses?
Virus particle structure Genome Replication features Serology Stability
what is a nucleocapsid?
RNA or DNA in a core that is protected by a protein coat (capsid)
Nucleocapsid is comprised of repeating protein subunits called _______
capsomeres
what are envelopes?
virus-modified cellular membranes acquired upon exit from host
what can render an enveloped virus noninfectious?
exposure to lipid solvents in the laboratory
the ______ of enveloped viruses may differ between viruses
nucleocapsids
what are the different types of single-stranded RNA?
Plus sense ssRNA
minus sense ssRNA
Ambisense
name the different structures of viral genomes
Linear
Circular
Segmented
Diploid
ssDNA hairpin is an example of what?
replication of viral genome
“rolling hairpin replication”
_____ rolling circle replication takes place on circular genomes of viruses
dsDNA
The positive strand RNA viruses’ function in same sense as ____
mRNA.
Before negative strand RNA can be translated, they must serve as template for what?
an RNA polymerase
the mirror image of a negative strand RNA will be the same as what?
positive strand RNA
what is the definition of viral attachment?
Binding of a virus receptor to a cellular receptor
T/F: viral receptors usually do not mimic cell receptors normal ligands
true
the binding of a virus to a cell receptor can cause what?
signaling molecule release
cell adhesion
transport inside the cell
_________ is a major determinant of virus tropism (host range)
Attachment
____ ____ is a major factor in the eradication of a virus
Host range