Notes from Class period of 9 - 21 - 09

I. E. coli bacteria are killed by a virus
Virus = T4 bacteriophage
Infection of E. Coli w/ T4 Bacteriaophage:
T4 bacteriophage adheres to a protein in the outer membrane of E. coli
Takes over The Enzymes needed for DNA replication. Also uses ribsomes
Poke a hole through the cell and through the hole it injects its DNA
T4 DNA: copied by bacterial enzymes and translated by bacterial ribosomes
Result: gives many many many copies of the T4 bacteriophage iside the bacterium (E. coli)
E. Coli once been used blows up. (lysis)
Once dies virus particles are released to infect E. coli
Experiment We are starting this week;
Looking at:
• can E. coli become resistant to T4 Bacteriophage
• Assuming they do become resistant why do they become resistant
Are they “Immune” after virus Attack and able to pass that acciqured immunity on to offspring.
If become “immune” is it not because they get strong but just fundamentally lucky that allows the to survive the attacks. “is it that some E. coli are randomally “born” resistant to T4
Are ribosomes a good target for antibacterial drugs?
5. Bacterial adhesion to surfaces
a. “Adhesins” are usually intergral or peripheral membrane proteins
Adhesins: membrane/cell wall proteins used to stick to surfaces: typically peripheral membrane proteins
Ex. Adhesins on the ends od pili
b. Pili – some but not all bacteria have, retractable parts (extensions that allow a bacterium to pull itself along a surface) another thing they are used for is transferring plasmids.
i. Attachment to surfaces and motility

ii. Use in conjugation (bacterial sex) by some species

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