Exam 3 Quiz 1 Flashcards
monosaccharides
one sugar unit
-glucose
-galactose
-manose
disaccharides
two sugar unit
-sucrose, lactose, maltose
polysaccharides
many sugars, starch
phenol red broth tubes + lactose
-pH indication
-show acidic environment due to fermentation
-need to use different tubes for each sugar
what color does acidic show up in phenol red broth tubes
yellow, if bubble there is CO2 production
products seen in fermentation
-alcohol
-CO2
-acid
Triple sugar iron agar slant
-Kliger agar slant
-3 sugars: glucose 0.1%, lactose 1%, sucrose 1%
-stab method
-not definitive for unknowns
if glucose used
butt yellow, pink slant
sucrose and/or lactose used
slant will be yellow
CO2 production in triple sugar agar slant
-splinter going through agar or pushing up
iron in triple sugar iron agar slant
-used to determine if bacteria expresses thiosulfate reductase (enzyme that helps reduce sulfur)
thiosulfate
will produce H2S if thiosulfate reductase present, smells, but not definitive
ferrous ammonium sulfate in triple sugar iron agar slant
reacts with H2S and forms black precipitate
oxygen requirements
thioglycollate broth
thioglycollate broth ingredients
-sodium thioglycollate (reduce O2 to H20)
-agar
-redox indicator
aerobes
require O2, seen at top of tube
faculatative aerobe
prefers O but can exist throughout, mostly at top but also throughout tube
aerotolerant
doenst need O2 but tolerates it, exists equally throughout tubr
anaerobe
will die in O2, seen at bottom of tube
polysaccharide
-too large to get accross cell membrane
-uses exoenzyme (amylase) to break it up (outside cell)
starch plate
-zone of clearing shows that the starch has amylase present.
-add iodine, cover surface of plate for at least one minute
motility determination
-using semi-solid agar deep
-inoculating needles and stab agar
semi solid agar deep
-0.8%agar (solid agar is 1.5%)
-see cloud of growth if motile
-if not motile then bacteria will be nice and tight
To make motility visible
-2,3,5 tetraphenyltetrazolium chloride (TCC)(colorless when added) as bacteria grow it incorporates into TCC and reduces it forming insoluble red pigment (formazan)
