Lecture 3 Flashcards
(53 cards)
Growth means what?
An increased number in cells (replication)
Cells elongate twice their length and then form what down the center?
Septum
Growth by binary fission means what?
2 cells from 1
Generation or doubling time means what?
The time to complete one entire division by binary fission
Which types use binary fission for growth?
Archea and prokaryotes
Generation process =
Cell elongation, septum, completion of septum
Generation time depends on what?
Available nutrients, environmental signals, and the number of bacteria already present (usually much slower exposed, but can be fast in a lab)
E. Coi can double how often under lab conditions?
every 20 minutes
Why do cells generate an increased amount of macromolecules during binary fission?
So the cells can thrive as soon as they separate (no growing, parenting, etc…they must be independent and fully functional)
Cells without MreB are what shape?
Spherical so coccus
Sterilization means what?
Total destruction of any and all microbes
Sterilization types?
physical, gas vapor, chemical
Example of physical sterilant?
moist or dry heat like incinerations in the lab for instruments
Example of gas vapor sterilant?
Hydrogen peroxide
Example of chemical sterilant?
Peracitic Acid
Pasteurization
controlled heating of a substance to reduce microbes. It does not kill all microbes, but kills many pathogenic microbes.
Disinfectant types
high, medium, low
What’s an example of high disinfectant and what’s it used for?
for items in invasive surgical procedures like surgical instruments, chlorine
What’s an example of intermediate disinfect and what’s it used for?
Used a lot to fight covid because it dissolves membrane lipids - alcohols, lyson, iodine
What’s an example of low disinfectant and what’s it used for?
To clean up after cooking in a kitchen or non-critical instruments like a blood pressure cuff or stethoscope
What’s used to sterilize instruments in lab?
Flame
solid media is prepared by adding what to the liquid media?
Agar gel
What degree is best for incubation in the lab?
37 degree C or room temperature for some bacteria
Pure culture vs. contaminated?
You have a pure culture if only one or the intended organism grows in the culture. If several bacteria grow in the culture, it’s contaminated.
