Portage Learning, Microbiology Module
6
Portage Learning, Microbiology Module 6
Study
virus
a small, non-cellular particle that cannot replicate unless inside a living host cell
obligate intracellular parasites
unable to replicate on their own
2 components of a virus
genomic material comprised of either DNA or RNA and a capsid
capsid
a membrane-like protective structure that contains the genetic material, similar
to the nucleus of a eukaryotic cell
are viruses prokaryotic or eukaryotic?
Neither, they are acellular
Viral genomes can be either ___________-stranded and may be found in
_________ arrangement
double- or single- / circular or linear
envelope
an additional layer around the capsid, derived from the host cell membrane and
serves as an additional barrier to the external environment
naked (non-enveloped) virus
a virus simply surrounded by the protein capsid
The overwhelming majority of animal viruses are __________________ whereas
the majority of plant or bacteria-infecting viruses are not.
Enveloped
, Portage Learning, Microbiology Module
6
Differences in ________________ can also significantly influence the shape and
appearance of the virus.
virion composition
smallpox virus
an enveloped, ~ 200 nm long and has a distinct dumbbell shaped viral capsid
poliovirus
non-enveloped and only ~30 nm in diameter
Differences between viruses are best visualized via an ____________.
electron microscope
paramyxoviruses and orthomyxoviruses
both enveloped, spherical and ~100-150 nm in diameter but vary drastically in
composition and function
paramyxoviruses
the causative agent of measles and mumps, contain a single-stranded linear
genome and fuses with the host cell membrane to initiate entry and viral
replication
orthomyxoviruses
the causative agent of the flu, contain eight segments of RNA and enters the host
cell via endocytosis
Viruses also require ___________________ in order to successfully replicate
host cell enzymes
Outside of a host cell viruses have no metabolism and are essentially
___________.
dormant
viral envelope
6
Portage Learning, Microbiology Module 6
Study
virus
a small, non-cellular particle that cannot replicate unless inside a living host cell
obligate intracellular parasites
unable to replicate on their own
2 components of a virus
genomic material comprised of either DNA or RNA and a capsid
capsid
a membrane-like protective structure that contains the genetic material, similar
to the nucleus of a eukaryotic cell
are viruses prokaryotic or eukaryotic?
Neither, they are acellular
Viral genomes can be either ___________-stranded and may be found in
_________ arrangement
double- or single- / circular or linear
envelope
an additional layer around the capsid, derived from the host cell membrane and
serves as an additional barrier to the external environment
naked (non-enveloped) virus
a virus simply surrounded by the protein capsid
The overwhelming majority of animal viruses are __________________ whereas
the majority of plant or bacteria-infecting viruses are not.
Enveloped
, Portage Learning, Microbiology Module
6
Differences in ________________ can also significantly influence the shape and
appearance of the virus.
virion composition
smallpox virus
an enveloped, ~ 200 nm long and has a distinct dumbbell shaped viral capsid
poliovirus
non-enveloped and only ~30 nm in diameter
Differences between viruses are best visualized via an ____________.
electron microscope
paramyxoviruses and orthomyxoviruses
both enveloped, spherical and ~100-150 nm in diameter but vary drastically in
composition and function
paramyxoviruses
the causative agent of measles and mumps, contain a single-stranded linear
genome and fuses with the host cell membrane to initiate entry and viral
replication
orthomyxoviruses
the causative agent of the flu, contain eight segments of RNA and enters the host
cell via endocytosis
Viruses also require ___________________ in order to successfully replicate
host cell enzymes
Outside of a host cell viruses have no metabolism and are essentially
___________.
dormant
viral envelope
