Lec 1 - 3 - Bacteriophages Flashcards
bacteriophages are the basis for blank technologies
recombinant dna (T4 ligase, T7 polymerase, cloning etc)
this alters bacterial virulence properties
lysogenic conversion
many microbes are harmless because they cant synthesize their blank
toxin
size of t2 bacteriphage
65 nm
size of hemoglobin molecule
15 nm
each phage attaches to one blank cell
bacteria cell
t phages and lambda are blank nucleic acid composition
double stranded dna
linear phage for sequencing used in cloning
m13 (ssDNA)
primary objective of phages is blank
replication
steps for a t4 phage life (lytic)
adsorption, penetration, replication
bacteriophages can be either blank or blank
lytic, temperate
t4 binds to blank during adsorption and then blank is made
e coli, LPS
the “legs” of the bacteriophage that binds and finds a cell to bind to
fembrils
steps of phage morphogenesis
preferential mRNA synthesis DNA synthesis protein synthesis incomplete head assembly DNA packaging tail addition maturation lysis of cell
period of time from immediate point of absorption to phage release
latent period
absorption to mature phage particles produced
eclipse period
temperate bacteriophage is aka blank
lysogenic
temperate bacteriophage actually blank itself into the genome or is floating in cytoplasm
incorporates
when conditions become adverse, lysogenic bacteria become blank
lytic
the model organism for a temperate bacterophage
bacteriophage lambda
lambda dna goes from linear to circular via blank
COS sites
sticky ends of the lambda dna is blank rich ssDNA
GC
the sticky ends of lambda dna are blank of each other
complements
sticky ends are gc rich because they have blank so they are stronger than AT
3 H bonds
four promoters that decide whether lytic or lysogenic
PL, PR, PRE, PRM
promoter in charge of RNAP for transcribing genes for lysis on left
PL
promoter in charge of RNAP for transcribing genes for lysis on right
PR
repressor of PL and PR transcription but activates PRM
cI
protein that is an inhibitor of cI; anti repressor
Cro
lysogenic cycle is from blank activation
PRE
lytic cycle is from blank activation
PR
protein transcribed in lysogenic cycle
cI
protein transcribed in lytic cycle
CRO
three factors of lysogeny
attP, attB, Int
attachment phage site on phage
attP
attachment bacterium site
attB
phage integrase protein
Int
attP and attB are both recognized by blank whch then recombines them into attBP
Int
lambda has developed a blank immunity
superinfection
lytic infection is blocked by pre existing blank
cI
lysogenic infection blocked by lack of blank sites because they have all been transformed to attBP
attB
lambda jumps ship from the lysogenic phase to become lytic via
excision which is the opposite of integration
