Chapter 8 Viruses And Virology Flashcards
Capsid
Protein shell that surrounds the genome of a virus particle
Capsomere
The subunit of a capsid
Concatemer
Two or more linear nucleic acid molecules joined covalently in tandem
Early protein
A protein synthesized soon after virus infection and before replication of the virus genome
Enveloped
In reference to a virus, having a lipoprotein membrane surrounding the virion
Host cell
A cell inside which a virus replicates
Late protein
A protein, typically a structural protein, synthesized late in virus infection
Lysogen
A bacterium containing a prophase
Lysogeny
A state in which the viral genome is replicated in step with the genome of the host
Lytic pathway
The type of virus infection that leads to virus replication and destruction of the host cell
Bacteriophage
A virus that infects bacterial cells
Middle protein
Protein with either a structural or catalytic function synthesized after the early proteins in a virus infection
Nucleocapsid
The complex of nucleic acid and proteins of a virus
Overlapping genes
Two or more genes in which part or all of one gene is embedded in the other
Plaque
A zone of lysis or growth inhibition caused by virus infection of a lawn of sensitive host cells
Prophage
The lysogenic form of a bacteriophage
Provirus
The genome of a temperate or latent animal virus when it is replicating in step with the host chromosome
Replicative form
A double-stranded DNA molecule that is an intermediate in the replication of viruses with single-stranded DNA genomes
Retrovirus
A virus whose RNA genome is replicated via a DNA intermediate
Reverse transcriptase
The retroviral enzyme that can produce DNA from an RNA template
RNA replicase
An enzyme that can produce RNA from an RNA template
Rolling circle replication
A DNA replication mechanism in which one strand is nicked and unrolled for use as a template to synthesize a complementary strand
Temperate virus
A virus whose genome can replicate along with that of its host without causing cell death, in a state called lysogeny (bacterial viruses) or latency (animal viruses)
Titer
The number of infections virions in a viral suspension
Virion
The infectious virus particle, the viral genome surrounded by a protein coat and sometimes other layers
Virulent virus
A virus that lyses or kills the host cell after infection
Virus
A genetic element containing either RNA or DNA surrounded by a protein capsid and that replicates only inside host cells
How does a virus differ from a cell?
Shape (typically smaller), genome length and the amount of genes encoded based on RNA or DNA usage, cannot replicate on its own and needs a virion to survive outside host cell
Why does a virus need a host cell?
Because it relies on the host cell’s energy for energy, metabolic intermediates, protein synthesis
