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virus is made up of?
genome and capsid
smaller protein units that make up the capsid
the genome and the capsid
addition items of a virus.
envelope and spikes
an enclosing structure similar to membrane that encloses a host cell
at which stage is the enveloped acquired?
the last stage of replication
projections from envelope to help make contact with the host's cell
virus is ...
a core of nucleic acid, have protein covering, some with envelope, no chemistry, takes up no nutrients, no waste, no metabolism, BUT replicates
what are some viral shapes?
- helical viruses
- -icosahedral viruses
- -complex viruses
helical viruses are...
- tightly wound coil
- ex. rabies virus, measles virus
- polyhedron with 20 triangular faces
- ex. herpes virus, parvovirus, poliovirus
complex virus ...
eg. influenza virus, smallpox, bacteriophage
components of a virus?
capsid, genome, capsomeres, envelopes spikes
stages of replication
- 1. attachment
- 2. penetration
- 3. uncoating
- 4. synthesis
- 5. assembly
- 6. release
What stage is there the virus anchors on to receptor sites on the host?
At this stage, the cell eventually break out
at this stage, the capsid is removed
at this stage, the genome passes thru the host membrane
at this stage, the affected makes the virus
at this stage, everything's put together after the viral parts are complete
what is the virus doing to host?
- -inhibit host's DNA/RNA/protein synthesis
- -disrupt chromosomes
- -high concentration of viral proteins inside host, which makes it toxic
acute infections (viral infection)
come on quick but last for short duration
persistent infection (viral infection)
can last many years
chronic virus infection.
- virus is almost always detectable
- -shows clinical symptoms, but mild or absent for long periods
latent infections (viral infections)
virus stops reproducing and remains dormant for some time; during latent stage, symptoms, viruses, and antibodies are not detectable
When viruses don't replicate, it's called ...
lytic cycle, aka lysogenic cycle
defense against virus.
antibodies, drugs, vaccine (weakened virus so body can rid of it)
- 1. inactivited: capsid's ok but no genome
- 2. intenuated: "live" virus that's working erally slowly, extremely slow replication
- 3. genetically engineered
simpler than virus, protein-like, and cause disease in plants
- -contrast wit prokaryotes, have a membrane bound nucleus
- -mitochondria (site for respiration)
- -chloroplasts, in photrophic cells, larger than mitochondria
- -other internal structures
- -external structures: flagella, cilia
unicellular, usually motile, lack cell wall, generally colorless, no chlorophyll, motility
active feeding form of protozoa
protective form or 'resting state' of protozoa
4 major groups of protozoa.
- 1. amoebas
- 2. flagellates
- 3. ciliates
- 4. sporozoa
- move by false feed "pseudopodia", heterotrophs (need organic carbon for growth); some have shell-like carings
- ex: forminifera: calcium carbonate, radiolaria: silicon dioxide
some phototrophic, most fundamental protists
diverse group of heterotrophic; move using hair-like cilia and some motile
all obligated parasites