Lecture 3 Flashcards
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.
Antisepsis
used to decrease the number of microbes on skin surface (hand sanitizer)
antibacterial soap has been proven to what?
Increase antibiotic resistance
Can fungi move?
No, they are not motile
Examples of fungi
molds, mushroom, yeasts
What do fungi eat?
dead, organic things and they consume by secreting enzymes that digest materials (melted icecream)
What’s a fungal infection type?
Ring worm
How to fungi reproduce?
Mainly asexually, but can sexually as well
How to protists move?
cell crawling like amoeba
Where do protists live?
decaying plant matter
What do protists eat and how?
Other microorganisms, mainly bacteria, and they consume by phagocytosis
Fungal pathogenisis types
- superficial mycoses = superficial surfaces of skin and hair (mostly cause skin discoloration)
- Cutaneous mycoses = infections of keratinzial layers of skin, hair, nails
- Subcutaneous mycoses = deeper layer (cornea, muscle, connective tissue)
- Endemic mycoses = usually in lungs and are true pathogens
selective vs. differential medium in labs
selective medium contains compounds that inhibit growth of some micoorganisms, but not others
differential medium lets everything grow and contains indicators, usually a dye, that allows some organisms to change by chemical reaction
Growth cycle phases in lab
- lab phase
- exponential phase
- stationary phase
- death phase
FtsZ
Forms ring around the center of the cell at the septum. , assembles around the z ring, knows to be in the exact center of the cell because the Min C and Min D are at polar ends of the cell, then Min E directs the center formation.
ZipA
anchor that connects FtsZ ring to the membrane
FtsA
helps connect the FtsZ ring to the membrane, similar to ZipA
FtsK
mediates separation of the chromosomes to daughter cells after the cell elongates
FtsI
transpeptidase involved in septal peptidoglycan synthesis (penicillin binding protein 3)
Fts proteins are found in all prokaryotes and are required for cell division. True or False?
True
During binary fission, daughter chromosomes are attached to what?
Cytoplasmic membrane
Crescent in
Shape determining protein produced by vibrio shaped cells
Penicillin attacks the cell wall of bacteria during reproduction, specifically goes after what?
FtsI
Fungi are classified as what because they eat dead, organic matter?
Chemoorganatrophs
Conidia
Asexual spores, resist drying, changes colors, some branches reach up into the air
2 types of slime molds
Plasmodial and cellular
Most common opportunistic fungal pathogen
Candida
Cryptococcus neoformans
Can act as a pathogen, but typically affect the immunocompromised. It’s an opportunistic fungal pathogen.
Aspergillus spp
Opportunistic fungal pathogens, most common invasive fungal infection, found in soil, plants, decaying vegetation, etc.
Antifungal agents
Pills, injections, creams
