6.3 Bacteriophages Flashcards
What is a bacteriophage?
virus that infects bacteria
What is a bacteriophage also known as?
phage
What is the structure of bacteriophages?
icosahedral capsid and helical tail
What are tail fibers and where are they attached to?
attached to tail; fibrous extensions that aid in binding host cells
What will penetrate the host cell and what occurs?
helical tail and the viral genome is injected through the hollow helical tail into the cytoplasm
What must researchers do in order to culture viruses?
must co-culture with live cells since viruses require a host
What are the two forms of replication for bacteriophages?
lytic
lysogenic
What are lytic bacteriophages?
replicate within the host bacteria until is lyses, effectively destroying the host cell
What is the viral titer?
quantitative amount of virus present in the culture
What is the purpose of knowing the viral titer?
allows researchers to carefully and effectively plan infectious experiments
What happens if there is too much virus in a culture?
immediately overwhelm and kill all host cells
What happens if there is too little virus in a culture?
take too long to generate detectable levels of newly produced viruses
What are lysogenic bacteriophages also known as?
temperate
What are lysogenic bacteriophages?
exist in a non-replicative state such that the viral genome is integrated into the host genome
What is a prophage?
a bacteriophage that has integrated its genome into the host genome