Ch 9 - Virology Flashcards
genetic element that cannot replicate independently of a living (host) cell
Virus
extracellular form of a virus
virion
are most viral genomes circular or linear?
mostly linear
the protein shell that surrounds the genome of a virus particle
capsid
subunit of the capsid
capsomere
complete complex of nucleic acid and protein packaged in the virion
nucleocapsid
virus that contains additional layers around the nucleocapsid
enveloped virus
viruses lyse host cells after infection
virulent mode
viruses replicate their genomes in tandem with host genome and without killing host
temperate mode
state where most virus genes are not expressed and virus genome (prophage) is replicated in synchrony with host chromosome
lysogeny
a bacterium containing a prophage
lysogen
release of virions from host cell does not result in cell lysis
persistent infections
delay between infection by the virus and lytic events
latent infections
conversion of normal cell into tumor cell
transformation
two or more cells become one cell with many nuclei
cell fusion
give an example of a retrovirus (ssRNA)
HIV
give an example of a hepadnavirus (dsDNA)
hepatitis B
Attachment of the virus to a susceptible host cell
adsorption
Entry of the virion or its nucleic acid
penetration
what are the phases of viral replication?
1) attachment
2) entry
3) synthesis of nucleic acids & proteins
4) assembly of capsids
5) release (lysis)
two phases of the latent period
eclipse and maturation
number of virions released
burst size
proteins necessary for replication of virus nucleic acid
early proteins
proteins that make up the structural components
late proteins
these viruses can undergo a stable genetic relationship within the host
temperate
viruses that are parasitic on other viruses
defective viruses
infectious RNA molecules that lack a protein coat
viroids
infectious proteins whose extracellular form contains no nucleic acid
prions
these infectious proteins infect the PrnP gene
prions
