chapter 5 and 11 p2 Flashcards
(78 cards)
What is generalized transduction?
It’s a process where bacterial DNA is transferred by a phage to a new host cell.
What happens when a phage infects the donor bacterial cell?
Phage DNA and proteins are made, and the bacterial chromosome is broken into pieces
How does bacterial DNA get packaged into a phage capsid?
Occasionally, pieces of bacterial DNA are mistakenly packaged during phage assembly
What happens when the donor cell lysates?
It releases phage particles containing bacterial DNA.
What happens when a phage carrying bacterial DNA infects a recipient cell
Recombination can occur, producing a recombinant cell with a different genotype.
What happens to the recombinant cell?
It reproduces normally, with a new genotype from both donor and recipient cells.
What happens during the attachment of a virus to the host cell?
The virus attaches to the surface of the host cell.
What happens after the virus injects its DNA into the host cell?
Lytic events are initiated, and the virus begins replication.
What is induction in the context of viral infection?
Induction is the activation of the viral genome from a latent state to initiate lytic events.
What occurs during the synthesis and assembly of phage components?
Viral components are synthesized, and new virions are assembled.
What happens when viral DNA is integrated into the host DNA
The viral DNA becomes part of the host’s genome and replicates with it.
What happens during cell division of a lysogenized cell?
Viral DNA is replicated along with the host DNA at each division.
What happens during lysis of the host cell?
The host cell bursts, releasing new phage virions.
What is a lysogenized cell?
A cell that carries a prophage (integrated viral DNA) in its genome.
What happens when a prophage exists in a galactose-using host?
The prophage exists in a host containing the gal gene, which is responsible for galactose metabolism.
What happens when the phage genome excises from the host?
The phage genome excises, carrying the adjacent gal gene from the host.
What happens when the phage matures and the cell lyses?
The phage matures and the cell lyses, releasing phage carrying the gal gene.
What happens when the phage infects a galactose-negative cell?
The phage, along with the gal gene, integrates into the recipient cell’s DNA.
What happens after the gal gene integrates into the recipient cell’s DNA?
The lysogenic cell can now metabolize galactose, becoming a galactose-positive recombinant.
What type of cell is created after the integration of the gal gene?
A galactose-positive recombinant cell is formed.
What is rolling circle replication in the context of the lambda phage genome?
It is a mechanism where the lambda phage DNA is replicated in a circular form, leading to continuous synthesis of new viral genomes.
What happens in the initial step of rolling circle replication?
The phage genome is nicked at a specific site, allowing the 3’ end to be extended while the 5’ end remains attached.
What happens after the nick in rolling circle replication?
The free 3’ end serves as a primer for continuous DNA synthesis, producing a long single-stranded DNA.