exam three (lysogeny transduction and lambda phage) Flashcards
____ are a vector for moving DNA by transduction
phages
in ______ transduction the host DNA is degraded
generalized
phages can get ____ DNA into its capsid which will carry that DNA into target cell and is transducing
HOST/ bacterial
a phage that has bacterial DNA will no longer be able to continue after transduction because it has no ____ DNA to infect
virus
phages have _____; a very specific target
tropism
The DNA of the host will do ___ ____ in target cell (tranduced)
homologous recombination
____ transduction is moving piece of DNA of specific sequence in a specific genome
specialized
lytic phages are responsible for ___
transduction
a lytic phage causes _____
lysis
a temperate phage can induce lysis or
lysogeny
instead of infection cycle where host DNA is chewed up, the lysogenic phage can make the bacterial genome take up ____ DNA
phage
phage DNA in host cell is called; cannot induce lysis
prophage
the prophage is then transcribed and translated in ____ cell
host
process of phage integrated DNA into bacterial chromosome
lysogeny
bacterium that contains prophage DNA in genome
lysogen
refers to phage DNA in bacterial chromsoome
prophage
induction causes phage to no longer be prophage but emerge and do lysis; what two facts can cause induction
UV light, chemical mutagens
____ are resistant to superinfection; cannot get re-infected with the same phage (one phage per bacteria)
lysogens (bacterial cell going through lysogeny)
phage induces a change in phenotype of its host
lysogenic conversion
a bacterial cell can be infected with _____ different types of phages
multiple
the bacteria V. cholera has what bacteriophage
CTX
the bacteria V. cholera + toxin has what bacteriophage
VPI
V. cholera bacteria without ____ phage cannot cause the disease cholera
CTX
The CTX phage as a prophage and V. cholera as a lysogen infects it and codes for the ____ which causes disease
toxin
_____ is the first phage that ineracts with V. cholera and puts its DNA inside of it, the VPI encodes a pillus and a receptor for CTX
VPI phage
The VPI once transcribed and translated on the bacterium has two proteins that code for what
Pillus and recteptor (pillus needed for toxin to be released; the receptor is the tropism for CTX)
CTX binds to receptor that ___ put on the surface, CTX induces lysogeny and makes toxin out of VPI pillus
VPI
sometimes in specialized transd. the _____ DNA is excised with phage genome
host
Once the phage with host DNA in it, will replicate its DNA ( and now host) will be picked back up by ____ ___ in the target cell
all phages
lambda phage has a tropism for
E. coli
lambda phage brings ___ ,____ ___ DNA
linear double stranded
the lambda phage DNA does what in cytoplasm of host cell
circularizes because of cohesive ends (cos)
left of regulators on lambda genome is
lysogeny
right of regulators on lambda genome is
lysis
c1 is a lambda repressor which induces
lysogeny
Cro will turn on the genes that lead to the event of
lysis
promotor right and left have ___ and ____ binding sites
-10 and -35
during infection initially promotor right and left are active making ___ and ___ protein
Cro and N
N protein is called
antiterminator
lysogenic enzymes being made are
N C3, Xis, Int
N makes sure both ____ are being made
transcripts
in a lysis scenario (right) the __ protein turns on every promotor that deals with lysis
Q
when phage goes lytic pathway a lot of ____ will be produced initially
Cro
Cro binds to what promoters when lytic pathway is selected
both
when Cro binds to left it ____ it; no more transcription
inhibits
lysis enzymes being made are
Q,O,P,C2,Cro
in lysogenic route, the C2 and C3 levels will matter, they will form a
heterodimer
the heterodimer of C2 and C3 bind to promotor for ____
integrase
this enzyme _____ will take the prophage DNA into host DNA (lysogeny)
integrase
the heterodimer of C2 and C3 bind to ____ promotor; which turns off cro production (estbalishing repression of lysis)
repression
the heterodimer of C2 and C3 bind to ____ promotor; to create antisense rna sequence block Q production
Q
C2 and C3 repress normal ____ phage process
lambda
when you have the promotor which established repression it makes ____
C1
C1 binds to promotor ___ and ____ to turn them off; keeps repression promotor going
right and left
C1 activates ____; produces more C1 (makes sure phage stays lysogenic)
PRM (promotor repressor maintenance);
initially there is a lot more ____ made than C1, because left and right will both be turned on
Cro
c1 binds more tightly than ____; only need a small amount to maintain repressionn
cro
if lots of C2 around then it will ensure enough ___ to compete with Cro
C1
C2 is susceptible to ___ ___ (chew up C2) ; less competition for Cro and pushes for lysis
host proteases
host proteases are present in ____ ____ environments
nutrient rich
in nutrient poor environments
fewer proteases; more C2 and C1; favor lysogeny (wait for environment to get better for phage to infect as many as possible)
the phage only lysis and kills the host when it is ______
advantageous (high nutrients)
when bacterial cell is damaged ____ can be started (no longer healthy host)
induction
SOS response excises DNA using
RecA
C1 self cleaves and removes itself from promotors; what happens next
lysis
excision, ____ and lysis
replication
after C1 self cleaves, ____ and excisionase are produced
Cro
C1 is expressed only during lysogeny and so C1 maintains repression, shuts down promotor right and left; if another lambda phage infected they would have to turn on promotor right and left, this is not possible because C1 is already there. This prevents _____
superinfection
