The following two questions were given to my classmates as preparation
for a midterm exam. I could use all resources available to answer these
questions. I would really appreciate any help, since most people on
these newsgroups are really knowledgeable. Besides, they'll be fun just
for practice.
1.
"TRACE O157:H7 E. COLI SOURCE" Suppose that you are the Centers for
Disease Control Agent assigned to find the apple orchard and then the
ranch whose cattle yielded the manure with the E. coli that caused the
unpasteurized apple juice outbreak of bloody diarrhea in Seattle in
October of 1996. Your target O157:H7 E. coli from purple colonies on on
cheap MacConkey's agar (unlinke other species of bacteria), and they
lyse red blood cells, forming clear "halos" around colonies on
moderately expensive blood agar plates (unlike non-pathogenic E. coli).
When your study is COMPLETED, you can confirm that the bacteria you have
found are the right ones, by sending them to the CDC lab for expensive
serological testing for the O157 lipopolysaccharide "O" antigen, and the
H7 flagellar protein variant. Outline your plan for tracing the source
of the outbreak, EXPLAINING along the way what you are doing, and why
you are doing it."
2.
"BACTERIAL PHOTOSYNTHETIC ELECTRON TRANSPORT. Most bacteria do not have
true "organelles" that form internal separate compartments inside
bacterial cells, but many have their photosynthetic electron transport
chains embedded in plasma membrane elaborations that concentrate
electron carriers and expand their capacity to do photosynthesis.
Outline the process of bacterial photosynthesis, and explain how it
works (using drawings (o)). (Draw internal membrane proteins (o))."
