lab practical 1 Flashcards
a spherical bacterium
coccus
rod-shaped bacteria
bascillus
a spiral-shaped bacterium
spirillum
visible mass of cells
colony
putting bacteria into a medium
innoculation
bacteria used in endospore staining
B.cereus
resting caused by lack of nutrients
endospore
- resistance to heat, radiation, acids & chemicals
- production of calcium dipicolinate
- cell dehydration
- spores can be destroyed in an autoclave
endospores
Differentiate between vegetative cells & endospores
endospore staining
protective protein coat of endospore
exosporium
endospore stain and coutnerstain
-malachite green
-counterstain: safranin
Waxy lipid, makes cells not permeable to most stains.
mycolic acid (acid fast)
primary stain in acid fast is
Carbolfuchsin
- stains acid-fast bacteria pink
Counterstain in acid-fast is
methylene blue
- stains non-acid-fast bacteria blue
decolorizer for acid fast staining
acid alcohol
bacteria used in acid-fast staining
mycobacterium smegmatis and stapholococcus
color of mycobacterium in acid fast stain
pink because they are acid fast
color of staph aureus in acid-fast stain
methylene blue bc they are non-acid fast
establish the difference between acid-fast & non-acid fast cells (differential stain)
acid-fast staining
- E.coli
- P.aeruginosa
- S.aureus
3 bacteria in the pure culture technique
- morphology
- arrangement
- internal structures
Good smears are important to observe
Two types of morphology
bacilli: rods
cocci: spherical
Two types of arrangements
staph: cluster
strep: chain
invented by christian gram to identify between bacteria and eukarya cells
gram staining
gram staining primary stain
crystal violet
gram staining mordant stain
gram’s iodine
gram staining decolorization
ethyl alcohol
gram staining counter stain
safranin
monotrichous flagella
one flagella
lophotrichous flagella
cluster of flagella at one pole
peritrichous flagella
flagella all over
amphitrichous flagella
flagella at both poles
located under the stage
collects and directs the light from the lamp to the slide being studied
condenser
Regulates the amount of light on the specimen
diaphragm (within condenser)
sides of microscope and used to bring objects into focus (up and down)
coarse adjustment knob and fine adjustment knob
After the crystal violet and iodine have been added to the slide
both gram +/- are purple
After alcohol has been added to the slide
gram + stays purple, but gram - is colorless
After safranin is added to the slide
gram + remains purple, gram - turns pink/red
how long do we store pure culture for
48 hours
at what temperature do we store pure culture at
37 degrees C
how many times do you go through a flame for heat fixing
3 times
- way to distinguish bacteria cells from eukaryotic cells
- first test used to identify an unknown species of bacteria
- differential stain based on cell wall structure composition
why is gram staining important?
bind crystal violet in gram-positive cells; insoluble
gram’s iodine
diplococci
staphylococci
streptococci
chain of bacilli
spirilla
spirochaetes
what method is pictured
quadrant streak plate method
what is labeled A
endospore
what is labeled B
free spores
what is labeled C
vegetative bacterial cells
pure culture techniques: E.coli
white; found in feecle matter
- gram negative
- rod shaped
pure culture techniques: P.aeruginosa
translucent green; found in environment
- gram negative
- rod shaped
pure culture techniques: S.aureus
yellow; found on the body
- gram positive
- cocci
what technique is pictured
pour plate (dilution)
endospore staining: vegetative cells will be ____ & endospores will be ____
pink; green
high heat & high pressure
autoclave
determination of a bacteriophage titer: organisms
E. Coli B & T4
viruses infecting bacteria cells “bacteria eater”
bacteriophage
- are obligate intracellular parasites
- have to invade a host cell to replicate and reproduce
- lack any metabolic machinery and protein sythesis
bacteriophage
single viral particle
virion
- infects E. Coli B exclusively
- lyric infection
- productive infection
- ability is used in phage typing of pathogens
T4 bacteriophage
number of produced virion
burst size
bacterial growth
confluent lawn
clearing of bacteria in a lawn due to lysis
plaques
determined by counting plaques’ number of viral particles
plaque forming units (PFUs)
motility determination: organisms
bacillus cereus & Klebsiella pneumoniae
what causes bacterial motility
- occurs in rod- and spiral- shaped bacteria
- almost never occurs in cocci
- flagella (movement in response to chemotaxis)
true movement from point A to B
chemotaxis
is caused by current movement under the cover glass
- caused by molecules bombarding cells
- results in “juggling” motion
brownian motion
- filament
- hook
- shaft
- gram positive bacteria: MS ring
- gram negative bacteria: MS, L & P
- basal body
- proton motive force induces MS ring rotation
flagellum components
amphilophostrichous flagella
a lot of flagella at both ends