CMMB 343 Exam Study Guide with 100% Correct Answers | Verified | Latest 2024 Version

CMMB 343 Exam Study Guide with 100% Correct Answers | Verified | Latest 2024 Version How does phi6 penetrate the host cell? - because it is an enveloped phage, it uses the entry and uncoating model that relies upon spike-protein mediated endocytosis - once in the vesicles, it releases the viral particles and proteases digest the capsid coat, lysing the vesicle, and releasing the phage genome into the cytoplasm Which protein is the plug at the end of the tail tube in T4, preventing DNA from leaving the tail tube to enter the host? gate 2 = gp29 Do all phages have tails? No - phi6 uses the spike-mediated endocytosis as it is enveloped How does T4 take over the host transcriptional/translational machinery following early gene expression? How does this relate to how T4 manages to overcome the host defense mechanisms of preventing foreign DNA incorporation? To overcome host defense, T4 uses hydroxymethylation of cytosines which then serves as a site for glucosylation - so all T4 DNA in E. coli has glucose molecules on its cytosines To destroy all host DNA, T4 produces a nuclease that digests al DNA that is not glucoslyated What is the burst size for T4? 200 viral particles/ infected E. coli host cell What is required to make opines? Ti plasmid --> induces formation of the Crown Gall tumor What are the differences between hopalines and octopines? Two types of opines... octopines: are an arg-ala derivative that has an unusual peptide bond that can't be metabolized by any cell who doesn't carry the Ti plasmid