Chapter 13 Flashcards
viruses are obilgatory intracellular
parasites
viruses require a living host to
multiply
viruses contain DNA or RNA or both or one of the other?
contain one of the other
viruses have a protein
coat
viruses have no
ribosomes
do viruses have ATP generating mechanisms
no
host range is the spectrum of host cells a virus can
infect
most visas infect only specific types of cells in one
host
the fact vises only infect specific types of cells is determined by
specific host attachment sites and cellular factors
bacteriophages are viruses that infect
bacteria
animal viruses the receptor is on the
plamsa membrane
virion
complete, full developed viral particle
in a virion the DNA or RNA can be single or double stranded but what other 2 shapes could it be
linear or circular
virion have a capsid protein coar made of
capsomeres
virion have spikes which re
projections from outer surface
virion spikes are reliable and used for
identifcation
virion helical virueses
hollow, cylindrical capsid
virion polyhedral viruses
many sided
what types of diseases have helical viruses
rabies and ebola
what type of disease has a polyhedral virus shape
polio
helical and polyhedral viruses can be
enveloped
enveloped helical example
flu
enveloped polyhedral example
herpes
complex virues
complicated structures
virus genus name ends in
-virus
virus family names end in
-viridae
virus order names end in
-ales
viral species
group of viruses sharing the same genetic information and ecological niche (Host)
virus are group according to how their ____ is produced
mRNA
virus subspecies are designated by a
number
viruses must be grown in
living cells
bacteriophages are grown in
bacteria
bacteriophages form _______ which are clearings on a lawn
plaques
each bacteriophages plaque corresponds to a single virus and can be expressed as ______-_____ _____
plaque forming units (PFU)
the three main ways to grow animal viruses in the lab
in living animals
in cell cultures
in emqryonated eggs
what is the most convinent way to grow viruses
culture media
when we grow viruses in emqryonated eggs the virus is injected into the egg and viral growth is signaled by
changes or death of the embryo
when we grow animal viruses in the lab in cell cultures the tissues are treated with ________ to separate the cells
enzymes
when we grow animal viruses in the lab in cell cultures virally infected cells are detected via their deterioration known as
cytopathic effect (CPE)
when we grow animal viruses in the lab in cell cultures ________ cell lines are used
continous
viral identification
cytopathic effects, serological tests, nucleic acids
what is the most common viral identification
serological tests
type of serological test
western blotting reaction
western blotting
reaction of the virus with antibodies
for a virus to multiply it must do 2 things
must invade a host cell
it must take over the hosts metabolic machinery
the growth curve to see viral multiplication is called
one step
multiplication of bacteriophages 2 cycles
lytic cycle and lysogenic cycle
lytic cycle
phage causes lysis and death to host cell
lysogenic cycle
phage DNA is incorporated in the host DNA, phage conversion, specialized transduction and host cell remains alive
stages of lytic cycle in bacteriophages
attachment stage, penetration stage, biosynthesis stage, maturation/assembly stage, release stage
lytic cycle attachment stage:
phage attaches to the ____ ___
host cell
lytic cycle penetration stage:
phage penetrates the host cell and then injects ___
DNA
lytic cycle biosynthesis stage:
the phage causes the host DNA to break into ____ _____. The phage then uses the host machinery to synthesize new copies of its DNA
small pieces
lytic cycle maturation/assembly stage:
phage components are assembled into _____
virions
lytic cycle release stage:
the cell ____, releasing the phage virions that go on to infect other cells
lyses
temperate bacteriophages go through what cycles
lytic and lysogenic
the lysogenic cycle of temperate bacteriophages phage DNA forms a ______, which can either replicate and be transcribed to produce _____ _______ in the lytic cycle or can proceed to lysogenic cycle
circle, phage components
the lysogenic cycle starts after ________ stage of lytic cycle
biosynthesis
in the lysogenic cycle, the phage DNA intergrates within the bacterial ________ by recombination, the inserted phage DNA is called a ________
chromosome, prophage
most of the phage proteins are repressed by two _______ proteins that are products of the phage genes
repressor
in the lysogenic cycle the prophage is excised from the host chromosome in a process called _________
induction
in the lysogenic cycle induction can occur spontaneously through __________ or some other genetic event or through the action of UV light or curtain chemical
recombination
in lysogenic cycle whenever the bacterium reproduces the prophage is
copied
T even bacteriophages the lytic cycle
attachment:
phage attaches by the tail fibers to the host cell
T even bacteriophage the lytic cycle
penetration:
phage lysozyme opens the cell wall; tail sheath contracts to force the tail core and DNA into the cell
T even bacteriophage the lytic cycle
biosynthesis:
production od phage DNA and proteins
T even bacteriophage the lytic cycle
maturation:
assembly of phage particles
T even bacteriophage the lytic cycle
release
phage lysozyme breaks the cell wall
what cycle do bacteriophage lambda go through
lysogenic cycle
lysogeny
phage remains latent
inserted phage DNA is known as a
prophage
bacteriophage lambda the lysogenic cycle results in phage conversion
the host cell exhibits new properties
results of bacteriophage lambda lysogenic cycle
lysogenic cells are immune to reinfection by the same phage
phage conversion which is when the host cell may exhibit new properties
make specialized transduction possible
the lysogenic cycle goes through _________ transduction
specialized
in specialized transduction specific bacterial genes transferred to another bacterium via a
phage
specialized transduction changes
genetic properties
multiplication of Animal Viruses
attachment
viruses attach to the cell membrane
how do animal viruses gain entry into the cell
receptor mediated endocytosis or fusion
multiplication of animal viruses
biosynthesis
production of nucleic acid and proteins
multiplication of animal viruses
maturation
nucleic acid and capsid proteins assemble
