BACTERIOPHAGE VIRUS

Multiply within bacteria eg. E.Coli Isocohedral head and helical tail Contain DNA Phage rep time: 20-40 mins (50-200)

Lytic Cycle: Virus goes inside, multiplys and releaseLysogenic Cycle: Virus DNA becomes part of host DNA and grows

LYTIC CYCLE: Attachment: binds the receptors on bacterial cell wall Penetration: genome is injected Early replication: Genome starts to replicate and other components develop Late replication: Production of components progress aswell as enzymes Maturation: components are now assembled Release: Phage coded, enzymes breakdown peptidoglycon in bacterial cell wall causes lysis

Some phages don't cause lysis/death: lysogenic cycle Lysogeny: conclusion in which bacteria/viruses can coexist without damage to each other Virus incorporates it's DNA/RNA into a chromosome of the host cell Each time a cells chromosome is reproduced the virus is also propgated

LYSOGENIC CYCLE: Host DNA is not destroyed and viral genome remains latent in the cellInactive phage = prophage Prophage codes for proteins that suppress prophage genes and renders bacteria resistant to more of the same phages Prophage can be activated and excised later to enter a lytic cycle

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