9.23.2022. + 9.26.2022. Study Questions (part 2) Flashcards
phage reproduction either leads to… (2)
productive infection or latent state
describe the end results of a productive infection?
some kill the host, others don’t
a temperate phage either leads to…
lytic infection or lysogenic infection
whether prophage persists or lytic cycle begins depends on…
repressor and other regulatory proteins
repressor and other regulatory proteins determine…
whether prophage persists or lytic cycle begins
what is a prophage? (2)
- latent form of a temperate phage
- phage DNA usually inserted into host chr
the latent form of a temperate phage is called…
prophage
what is a temperate phage?
bacteriophage that either produces a 1. productive infection or 2. latent infection
what does a repressor do?
why is a repressor important?
- prevents expression of genes required for excision
- essential for maintaining lysogenic (latent) state
lysogenic state, aka
latent state
latent state, aka
lysogenic state
how to excise phage DNA from bacterial DNA?
phage induction
what is phage induction?
a way to excise phage DNA from bacterial DNA
what does phage induction accomplish?
lets phage escape from damaged host
how does phage induction work? (4)
DREP
DREP
1. damage lysogenic culture with UV light
2. SOS repair system responds to damage by activating enzyme that destroys repressor
3. with repressor gone, prophage is excised from chr., allowing phage to enter lytic cycle, and
4. a productive infection results
