Phages Flashcards
(25 cards)
what is a phage
a virus that infects bacteria
what are the two life cycle types for phages
lytic - replicates until cell lysis
lysogenic - intergrates and forms a prophage with the bacteria
what is a prophage
a bacterial chromosome with intergrated phage genomes
what is a temperate phage
a phage that can have both lytic and lysogenic phases
what is a virulant phage
a phage with only lytic phases
what are the life stages of a lytic phage
attachment to surface membrane recepotors
injection of viral dna or rna
new phages produced on mass
phages released by lysis
how can you isolate lytic phages
by using clearance zones on bacterial plates
what receptors do lambda phages bind to
they bind to maltose uptake channels
what are cos sites
sticky ends used for the circularization of lambda phage dna,dictates the size of the phage
what factors can cause the reactivation of lysogenic phages
uv radiation
nutrient stress
dna damage
antibiotics
ros
what is transduction
the transfer of dna from cells using phages
what are the differences between generalised and speciased transduction
specialised uses dna usually ajacent to the insertion site, while generalised can use any random fragment
what is the max insert on regular phage lambda and why
the regular phage is 49 kb, the max is 52, leaving 3kb of insert size
how do insetional and replacement vecotrs function
what is the m13 phage
a phage which can exist as both double and single stranded, and can act as a plasmid in a cell and be isolated as a single strand in phage heads
what type of growth does m13 phage cause
slow turbid growth
how does the m13 phage attach to cells
using the f plasmid pilus
what is the max insert size of m13 and what is it an example of
maximum insert size is 1500bps, it is a phagemid
what is phage display
by inserting the roi into the coat protein of a m13 phage, it can be detected using antibodies or other methods for activity of interest
what are high capacity fragments and what are important features of them
used to clone large fragments such as in genome mapping
selectable
cloning sites
recombinant identifyable
stable
what is a cosmid
a cosmid is a plasmid that has cos sites bonded to it, this allows for it to be digested, recombinated, and inserted into phage lambda heads for replication
what is a p1 and its p1 derived artificial chromosome
a bacteriophage with a large chromosome that replicates as a plasmid in a host, this can be used as an artificial chromosome and has a capacity of 150-300kbps
it requires an ecoli strain with a cre gene added to its genome
what is a bacterial artificial chromosome
a bac is a low copy plasmid that has been modifyed, such as the f plasmid, it is highly stable and allows for fragment 100-300 kbp
what are yeast artificial chromosomes
yeast artificial chromosomes have telomeres and centromeres like regular chromosomes
