Create an account
image remains in focus when changing from low power objective lens to high power objective lens
oil has the same refractive index as glass and will increase resolving power by reducing light lost from refraction
motile, using axial filaments, which are a type of flagella that originate from both ends of the cell and wrap around the cell body
"other" + "eating" - organisms which feed on other plants and animals, as oposed to autotrophs that use CO2
eukaryotic, nucleus, produce exoenzymes and absorb thier nutrients, lack tissue definition, have cell wall of chitin, propogate (multiply) by spores
structural, the form and structure of an organism considered as a whole
zygospores, ascopores, basidiospores; union of two parental nuclei followed by meotic division
goals of aseptic technique
no unwanted organisms in culture, you are not contaminated, no contaminates are left afterwards
resting, resistant, dormant structure formed inside some bacteria that protects form adverse environment; dehyrated with thick cells walls with extra layers
cover is held diagonally over the plate to protect the surface from any contaminates in the air
inoculated petri plates
incubated upside down to prevent moisture from condensing on the agar surface and spoiling or spreading inoculated organism
contains only a single kind of bacteria; able to study morphological, cultural and physiological characteristics
obtain pure cultures
streak plate and pour plate dilute bacteria to a point where a single cell gives rise to single pure colony
becomes liquid at 85 and resolidifies at 42. Good gel stability at high temperatures; made from polysaccharide of algae
reasons for thin slide prep
to visualize individual cells, their arrangment and details regarding microstructures; stains better
distinct reddish-purple granules with cells that show up when the organisms are stained with methylene blue
parallel arrangment of rod shaped cells "picket fence" (characteristic of corynebacteria)
slime layer, gycocalyx, protective role for certain bacteria like streptococcus pneumoniae, prevents phagocytosis by WBC, to attach to solid surfaces
take advantage of the fact that cells or structures within cells display dissimilar staining reactions that can be distinguished by the use of different dyes
gram positive bacteria
retain crystal violet-iodine complex through decolorization with alcohol; appear purple
gram negative bacteria
alcohol removes the crystal violet iodine complex; counterstain of safranin makes bacteria appear pink
for gram stain is iodine; forms complex with crystal violet that is insoluble in gram positive cells
acid fast bacteria that stains gram positive; representative of acid fast bacteria
allow bacteria to survive environmental conditions that are not favorabe for growth; resistant to heat, radiation, acids, and many chemicals such as disinfectants
forms gel that controls the amount of water that can enter the endospore, thus maintaining its dehydrated state
utilizes malachite green to stain the endospore and safranin to stain the vegetative portion
waxy material; complex lipid that is composed of fatty acids and fatty alcohols that have hydrocarbon chains up to 80 carbons in length; prevents routine stains
acid fast stain
diagnositc tool for Mycobacterium tuberculosis and Mycobacterium leprae (tuberculosis and leprecy)
carbolfushion mixed with phenol is heated, creates noxious fumes toxic to the eyes and mucous membranes
carbolfuchsin mixed with phenol (for permeability), then decolorized with alcohol, counterstained with methylene blue
test to determine the oxygen requirements by observing the nature of growth in the tube
study of protozoans, parasitic worms (helminths), and parasitic arthropods such as lice, mites and ticks
repesentative flagellate; mastigophora
Trichomonas vaginalis, Giardia lamblia, Trypanosoma gambiense
laboratory identification of the parasitic protozoans is usually made from microscopic examination of the trophozoite stage.
specimens containing the parasitic trophozoite stage are more readily available for classroom study than those containing the cyst stage.
result of ingestion of encysted larvae in the improperly cooked flesh of an intermediate host animal
observable traits, phenotype
Color of colonies, number of colonies, distribution of colonies on the plate.
good choices for genetic transformation experiments
non toxic, reproduces quickly, single cell organism
Genetically transformed cells
cells that have taken up the pGLO plasmid express the ampicillin resistance gene—these cells can survive on the plates which contain ampicillin.
determine success of transformation
The LB/amp (-) pGLO and the LB/amp (+) pGLO plates should be directly compared.
guide your interpretation of results in an experiment; usually a plate of your original without manipulation
so many bacterial on a plate that individual colonies are not present, looks like a complete covering of growth
how to determine ampicillin resistance
take some of the bacteria growing on the LB plate and
streak them on an LB/amp plate.
two factors that cause bacteria to glow green
The sugar arabinose turns on expression of the GFP gene by binding to a regulatory protein. When arabinose
is present, it facilitates transcription of the gene by RNA polymerase. Exposure to UV light causes GFP to
resonate, thereby giving off energy in the form of green light.
advantage of turning off a gene
Gene regulation allows for adaptation to differing conditions and prevents wasteful overproduction of unneeded proteins.
gram positive cocci, cause of staph infections, golden color, commensal on skin, produce enterotoxin
commonly-used bacterial indicator of sanitary quality of foods and water; almost exclusively of fecal origin and their presence is thus an effective confirmation of fecal contamination; E. coli and Enterbacter aerogenes
bacteria that indicates likelihood fecal contamination in water and the potential for serious disease
E. coli is a good indicator
occurs primarily in the intestines of of humans and warm-blooded animals and is not found routinely in soil or water; easily identified by microbiological tests; not as fastidous as the intestinal pathogens and survives a little longer in water samples
Most probable number
15 tube method, pattern of positive tubes and chart is used to ascertain the MPN of coliforms in 100 ml of water
plates of Levine EMB agar or Endo agar are inoculated from positive tubes to see if the organism is gram negative; media inhibits growth of gram positive
contains a fuchsin sulfite indicator that makes coliforms produce reddish colonies and confirms presence of lactose fermenting, gram negative bacteria; nonfermenters do not affect the color of the medium (lt pink)
Levine EMB agar
contains methylene blue that inhibits the growth of gram negative and E. coli will produce small colonies with green metallic sheen; E. aerogenes colonies are larger and no sheen
completed test for coliform
inoculate a nutrient agar slant and lactose broth with Durham tube. gram stain is made from slant
diluted sample of cells is counted under a microscope, counts live and dead; doesnt require growth in alternative media
standard plate count (SPC)
serial dilution, a portion is plated, dilution that produces CFUs between 30-300 are counted and multiplied by dilution factor
only counts live cells and CFUs may distort bacteria that grow in chains, media may bias bacteria that prefer other conditions
cause DNA to become deformed and polymerase is unable to replicate DNA strands beyond the formation
reasons endospores are resistant to UV light
DNA is protected by a small, acid soluble protien that binds to DNA and unique spore photo product is generated by UV light and functions in enzymatic repair of damage DNA
streak plate uniformly, paper disks containing concentrations of antibiotics/antimicrobials are deposited on agar surface, antimicrobial diffusion causes a concentration grandient and inhibits growth
zone size variation
due to diffusibility of agent, size of inoculum, type of medium and effectiveness of antibiotic/anitmicrobial
narrow spectrum antibiotics
Drugs effective against only one or a specific family of microorganisms.
used to kill or inhibit growth of microorganisms on inanimate objects, not effective on endospores
used to kill or inhibit growth of microorganisms in living tissue, not effective on endospores
observe liquefaction to determine if organism produced protease, an enzyme that degrades protien
observe the nature of growth to determine characteristics of growth like surface, subsurface, sediment and turbidity, faky or flocculent
observe color change to determine if nitrate was reduced to a gas or to nitrite; gas= dark red; zinc will react if nitrate is still present by turning black; nitrate reductase
observe color change and gas collection to determine if organism ferments a sugar
methyl red test
3-4 drops of methyl red into MRVP tube to detect acid produced by other fermentation acidic byproducts, red band across top indicates mixed acid fermentation
Sim citrate slant
detects citrate degrading; color change from green to blue to determine if organism used citrate as sole carbon source and produced ammonia
Tryptophan degradation test
observe presence of red band indicating the presence of indole, determines the organism can degrade amino acid to indole, pyruvic acid and ammonia
observe a color change to determine if the organism can breakdown urea into CO2 and ammonia
iodine complexes with starch and blue indicates presence of starch and that the organism did not hydrolyse starch, clear area around organism indicates organism hydrolyses starch
cleaves fatty acid from glycerol and lowers the pH of the agar to produce dark blue precipitate
Kleigers iron agar slant
observe color change to black precipitate to determine if organism can breakdown the amino acid cysteine to hydrogen sulfide
litmus milk test
organisms that ferment the lactose will turn litmus pink and organisms that degrade casein will release ammonia and turn the litmus blue
substance in the cell wall of mycobacteria and some norcardia that significantly affects staining properties
stains to react differently with different types of bacteria, used to distinguish bacterial types. Gram stain, acid-fast stain
narrow your search
important to complete morphological and characterizations before physiological testing
often added to test to detect acid/base byproducts of the specific degration, fermentation, metabolism
an enzyme that is secreted by a cell and that works outside of that cell. It is usually used for breaking up large molecules that would not be able to enter the cell otherwise
enzymatic degration of carbohydrates final electron acceptor is an organic molecule, oxygen is not required
Please allow access to your computer’s microphone to use Voice Recording.
Having trouble? Click here for help.
We can’t access your microphone!
Click the icon above to update your browser permissions and try again
Reload the page to try again!Reload
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Please upgrade Flash or install Chrome
to use Voice Recording.
For more help, see our troubleshooting page.
Your microphone is muted
For help fixing this issue, see this FAQ.
Star this term
You can study starred terms together