Review Sheet 2 Flashcards
Motility, Growth, Nutrition, Antimicrobial control, Bacterial Staining
4 Arrangements of Flagella
- Monotrichous
- Amphitrichous
- Lophotrichous
- Peritrichous
Monotrichous
1 Flagellum
Amphitrichous
2 Flagella, 1 on each end
Lophotrichous
Tuft of Flagella
Peritrichous
Flagella all over
3 Parts of Prokaryotic Flagella
- Filament
- Hook
- Basal Body
Filament (Prokaryotic Flagella)
- Long part
- Made of protein Flagellin
Hook
Connects filament and basal body at an angle
Basal Body
Embedded in a cell wall/plasma membrane. Motion is generated here.
Run and Tumble motility
Run- go in a direction
Tumble- stop and turn
- can* control how long the run is
- cannot* control the direction of the tumble
Counterclockwise flagellar rotation
Run
Clockwise flagellar rotation
Tumble
Brownian movement
Floating around
Eukaryotic v. Prokaryotic flagella
Prokaryotes- Flagellin
Eukaryotes- Microtubules, Dynien
Cillia
Short, lots of them
Flagella
Long, usually 1 or a few
Hanging Drop Slide
Indentation in slide to allow a drop of culture to be viewed. Best for showing motility
4 Stages of growth
- Lag Phase
- Log Phase
- Stationary Phase
- Death Phase
Lag Phase
In a new culture delay before growth starts
Log Phase
Max growth rate
Stationary Phase
Nutrients harder to find, growth stops because 1. No more nutrients 2. Inhibited by its own waste
Death Phase
It dies… duh.
Can’t be measured by spectrophotometry/OD600 because it can’t distinguish between living and dead cells
3 Ways to Measure Bacterial Numbers
- CFU
- Spectrophotometry
- OD600
CFU
Colony Forming Unit Spread sample, count colonies
Spectrophotometry
Measures Tubidity
- What % light goes through sample
OD600
- Absorbance/Scattering using 600 nm light
- Directly proportional to # of cells
What gives you actual # living bacteria?
CFU, the others also count dead bacteria.
10 Macronutrients
CHONPS Ca, Mg, K, Fe
Difference between macronutrient and micronutrient
Macro- Need to Survive
Micro- On the side
Leibig’s Law of the Minimum
Amount of growth is limited by least common nutrient or growth factor
Heterotroph
Cannot use CO2 as sole C source
Autotroph
Can use Co2 as sole carbon source
Phototroph
Gets energy from sun
Chemotroph
Gets energy from inorganic/organic compounds
Lithotroph
Gets electrons from inorganic source
Organotroph
Gets electrons from organic source
ABC pump
Uses ATP
Symporter/Antiporter
uses energy from one molecule to move another
How Fe is brought into the cell
Siderophores
Synthetic/Defined Media
Made from Scratch
Complex media
Includes extracts, other ingredients
Differential Media
Different growth for different organisms
Peptones
Proteins digested by peptin
Tryptones
Proteins digested by trypsin
Extracts
Stuff that is ground up and dried out. Like a cow in a blender.
Agar
Made from red algae. Not digestible. Solid up to 42˚C
Plates
You’re stupid if you don’t know this by now.
Broth
Same. Come on, get it together.
Slant
Used for measuring acid formation.
Deeps
Used for measuring gas formation
Shelford’s Law of Tolerance
Each organism has certain conditions (tolerances) in which it can live
Passive v. Active Transport
Passive- goes with concentration gradient
Active - requires energy
Sterilization
Everything is dead
Disinfection
Primarily kills present pathogens
Sanitization
Disinfection of a public place to meet some sort of health standard
Antisepsis
Killing enough to prevent sepsis of a tissue
- icides
Anything that kills (germicides, bacteriocides, fungicides, etc)
-Statics
prevents growth, but doesn’t kill (fungistatic, bacteriostatic, etc)
TDP
Thermal death point- how much heat does it take to kill everything?
TDT
Thermal Death Time- how long at a temperature does it take to kill everything?
D-value
Time it takes to kill 90% of everything at a certain temperature
z-value
change in temperature needed to change D-value 10 fold.
F-value
temperature needed to kill 90% in a given time
Autoclave
Moist heat. 121˚C for 30 min
Pastuerization
kills pathogens @63˚C for 30 min
UHT sterilization
Ultra High Temperature 150˚C for 15 sec.
Dry heat sterilization
Slow, less effective than moist.
Low Temperatures
Slow growth, doesn’t kill
3 kinds of filtration
- Membrane filter
- HEPA filter
- Laminar flow hood.
Membrane filter
Liquids- nylon 0.2µm filter
HEPA filter
Air filter, 0.3µm
Laminar flow hood
blows filtered air at you. Protects samples from you.
UV radiation
Works well on solid surfaces, such as a lab bench. Slow. Doesn’t penetrate well.
Ionizing radiation
Kills everything. “In addition to creating the Incredible Hulk, it goes through things”
7 Classes of antimicrobial controls
- Phenol (Lister)
- Alcohols
- Halogens
- Heavy metals
- Detergens
- Aldehydes
- Ethylene Oxide
Iodophores
Chemicals that slowly release Iodine
Chlorine/Sodium hypochlorite
Bleach. In water –> hypochloric acid, a strong oxidizer.
Negative staining
Stain everything around specimen
Usually with India Ink, Eosin, or Nigrosin.
Direct Staining
Stain the specimen
Why would you use negative staining?
To determine bacterial morphology without harsh staining or heat fixing techniques, or of the bacterium doesn’t stain well.
Why would you use direct staining?
Simple, easy to use, easy to see bacteria.
Smear
Dried bacteria from a broth or mixed with water on a glass slide, usually stained
How to prepare a smear?
- Spread from broth or mix with water on slide.
- Spread
- Air dry
- Heat fix.
- Stain/do other stuff to it. Then view.
Heat fixing
Run it over a flame to fix bacteria to slide. Kills them and can change cell morphology.
Gram staining distinguishes
A positive or negative gram stain. Nothing else. This typically means that there is peptidoglycan in the cell wall.
Primary stain
First stain. We used crystal violet.
Mordant
Iodine, increases interaction of bacterial cell and primary stain.
Counterstained
We used safranin. Stains the other bacteria pink.
Decolorizer
Ethanol.
Pinkish bacteria are….
Gram -
Purple bacteria are…
Gram +
Gram stain procedure steps:
- Primary Stain
- Mordant
- Decolorize (not too long)
- Counterstain
Rinse between steps.