Micro Lab Final Test Answers – Flashcards
Unlock all answers in this set
Unlock answersquestion
| Bacillus subtilis |
answer
| gram positive. bacilli-rod. produces amylase. forms endospores. strict aerobic-requires oxygen to grow. colonies with a raised and a dull surface. |
question
| Enterobacter aerogenes |
answer
| gram- negative. bacilli- rods. single. fat--> plump. in gramstain- dark red. oxidase- negative. large intestine, E. coli. |
question
| Escherichia coli |
answer
| gram- negative. bacilli-rods. facultative anaerobe. single. bipolar staining with methylene blue. in gram staining- colonies are light red. opportunistic pathogen. oxidase- negative. does not produce amylase. could produce catylase. |
question
| Proteus vulgaris |
answer
| gram- negative. bacilli- rod. |
question
| Serratia marcescens |
answer
| gram-negative. bacilli- rod. colonies are orange/red when grown at low temperatures. large, irregularly edged. |
question
| Pseudomonas aeruginosa |
answer
| gram- negative. bacilli-rod. obligate anaerobe. grown in endo agar. produce catylase. |
question
| Saccharomyces cerevisiae |
answer
| gram-negative. fungi. dimorphic. cocci-oval/elongated shape. reproduces by budding which you will most likely see- asexual, similar to binary fission but gets to unequal cells- budding yeast. |
question
| Mycobacterium tuberculosis |
answer
| red, acid-base stain. bacilli-rods. tend to clump together. grows as a very hard, granular colonnade. must include background color even if it's colorless. nonmotile, nonsporing, weakly gram-positive.; |
question
| Micrococcus luteus |
answer
| gram-positive cocci (round). Anaerobe. Colonies are canary yellow. Tetrade. Rod-like. |
question
| Mycobacterium spegmatis |
answer
| gram-positive (bacillus). colonies are slow growing and punctiform. has waxy cell walls so it's generally gram-nonreactive. use acid fast staining |
question
| Staphylococcus epidermidis |
answer
| gram positive sphere- cocci. facultative anaerobe. cluster/net-like. colonies are white, raised, circular, and entire. opportunistic pathogen. with gramstaining- colonies are purple. normally lives on skin. |
question
| Clostridium sporogenes |
answer
| spore-forming, gram-positive, anaerobe, bacilli-rod. colonies are irregular and rhizoid. viewed with transmitted light. forms endospores. obligate anaerobe. |
question
| Streptococcus faecalis |
answer
| gram-positive. aerobe tolerant. lactic acid producing bacteria. does not produce catylase. |
question
| ENDO agar |
answer
| media used to detect water contamination. contains color indicators that are grampositive inhibitors. detects lactose fermentors--> selective and differential, for gram negative. |
question
| Eosin Methylene Blue Agar |
answer
| media used for the isolation of fecal coliforms--> selective and differential, for gram negative |
question
| tryptic soy agar |
answer
| all purpose media |
question
| lauryl tryptose broth |
answer
| media used in the presumptive test for the presence of coliforms. lactose containing medium. bacteria, if aerogenic (gas produce) in this broth, are presumed coliforms. |
question
| fluid thioglycollate medium |
answer
| media that tests aerotolerance of bacteria. appropriate for a broad variety of aerobic and anaerobic organisms. oxidized portion- aerobic- turns pink. reduced portion- anaerobic- remains colorless. |
question
| starch agar |
answer
| media used to show how amylase breaks down the starch (using iodine) |
question
| brilliant green lactose bile broth |
answer
| media used in confirmed test of gas production in the water analysis. lactose broth medium. function: selective for gram negative--> has lots of sugar, shown if has turbidity, MUST use streak plate isolation. ALSO CAN USE TO DETERMINE IF LAURLY TRYPTOSE BROTH CONTAINS COLIFORMS. |
question
| macconkey's agar |
answer
| media that inhibits gram positive microbes. selective and differential medium containing lactose, bile salts, neutral red, and crystal violet. *used to isolate members of enterbacteriaceae. DIP N COUNT! |
question
| triple sugar iron agar |
answer
| differential agar in which bacteria that form hydrogen sulfide will blacken the agar |
question
| media |
answer
| nutrient solutions |
question
| solid media |
answer
| used for separation of bacteria and letting them grow in isolated colonies or for maintaining stock culture |
question
| liquefiable solid media |
answer
| colloidal suspension of nutrient material which can be liquefied with heat and poured as a liquid, or when allowed to cool, the medium can be used in a solid state. |
question
| semisolid media |
answer
| see if bacteria is motile or not. *used for medical specimens containing bacteria |
question
| liquid media |
answer
| used for cultivation of large quality of microbes |
question
| all-purpose media |
answer
| supports growth of most bacteria |
question
| differential media |
answer
| media in which biochemical products of some chemicals react with, creating a visible result in the colony or media |
question
| selective media |
answer
| inhibit the growth of some microbes |
question
| enrichment media |
answer
| contains nutrients that favor growth of certain organisms |
question
| synthetic media |
answer
| media in which the exact ion concentration of every chemical in the medium is known |
question
| non-defined media/chemically complexed |
answer
| media contained natural ingredients such as beef extract (*these are the type that we made in the lab) |
question
| dehydrated media |
answer
| standardized media prepared in large batches, desiccated, bottled, and sold. *all bacteria must have water, carbon, an energy source, nitrogen, and minerals |
question
| agar media |
answer
| solidifying agent used to physically, not nutritionally, support bacterial growth.; |
question
| autoclave |
answer
| a sterilizer employing super-heated steam under pressure |
question
| holding temperature |
answer
| temperature needed for media to be poured |
question
| pure culture |
answer
| contains only one kind of bacteria |
question
| contamination |
answer
| introduction of unwanted organisms |
question
| aseptic/sterile techniques |
answer
| procedure that both protects culture and protects the environment. *used to transfer bacteria so that the bacteria can have nutrients to grow on and escape their own toxic waste |
question
| colony |
answer
| the descendants of one cell growing together on a solid surface |
question
| flaming |
answer
| used to incinerate any organisms on the inoculating wire |
question
| pellicle |
answer
| suface membrane produced by organisms cultivated in broth that float on the top of the medium |
question
| sediment |
answer
| organisms that sink to the bottom |
question
| uniform fine turbidity |
answer
| uniformed cloudiness |
question
| flocculent |
answer
| clumping of organisms in broth |
question
| aerotolerance |
answer
| ability/inability to grow the presence of oxygen |
question
| obligate aerobes |
answer
| need oxygen- seen at the top of broth |
question
| facultative aerobes |
answer
| grow in presence/absence of oxygen |
question
| aerotolerant aerobes |
answer
| respire anaerobically even when oxygen is present |
question
| anaerobes |
answer
| doesn't matter- live throughout the media |
question
| microaerophiles |
answer
| survive only in environments containing lower than atmospheric levels of oxygen- grow in the middle |
question
| obligate anaerobes |
answer
| cannot grow with oxygen- inhibit the lower 2/3 of media |
question
| microscope |
answer
| device for magnifying objects that are too small to be seen with the naked eye |
question
| simple microscope |
answer
| one-lens magnifier |
question
| compound microscope |
answer
| microscopes that employ to or more sets of lenses |
question
| total magnification |
answer
| multiply the objective lens times the ocular lens |
question
| working distance |
answer
| the distance separating a specimen and your objective lens |
question
| condenser |
answer
| controls quality of light on microscope- concentrates the light and makes illumination of the specimen more uniform |
question
| microscopic field |
answer
| the area of the microscope slide that you see through a lens |
question
| resolving power |
answer
| ability to distinguish close-together objects, resolution, and clarity |
question
| parfocal |
answer
| lenses are adjusted so that the specimen remains almost in focus after the microscope is rotated the nosepiece to utilize a different objective lens |
question
| oil immersion steps |
answer
| high power, in focus- drop a drop of oil directly on smear, then rotate to oil immersion lens |
question
| objective lens then ocular lens |
answer
| magnified first by ____ to produce real image and then _____ to produce a virtual image. |
question
| photosynthetic |
answer
| able to make cellular molecule use light energy and CO2 |
question
| chemosynthetic |
answer
| able to construct cellular molecules using preformed organic molecules for carbon and energy |
question
| saprophytic |
answer
| living in dead/decaying organic material |
question
| aerotaxis |
answer
| the ability to move toward or away from chemicals, light, or oxygen |
question
| stained preparations |
answer
| the preparation applied to dead cells |
question
| unstained preparations |
answer
| preparation applied to living organisms- prepared by wet mount (prepared by placing a drop of liquid containing specimens onto a glass slide and covering it. **purpose: to determine motility) or hanging-drop (specimen hangs suspended from a coverslip into the indentation of a glass depression slide. **benefit: allows longer observation) |
question
| brownian movement |
answer
| a random bouncing that results from microbes colliding with molecules that are in constant motion with the liquid environment. **differs from motility, which is directed movement |
question
| prokaryotic cells |
answer
| tiny and lack a membrane-bound nucleus |
question
| cocci |
answer
| circles/spheres |
question
| rods |
answer
| lines |
question
| spirilla |
answer
| spiral |
question
| vibrios |
answer
| slightly curved rods |
question
| coccobacilli |
answer
| short rods |
question
| spirochetes |
answer
| flexible spirals |
question
| flagella |
answer
| threadlike organelles that propel organisms through liquid |
question
| refractile |
answer
| shiny |
question
| endospores |
answer
| tough, resting structures |
question
| conidia |
answer
| reproductive spores formed at the tips of branching filaments |
question
| taxis |
answer
| movement of motile organisms that are positive or negative (e.g. chemotaxis, phototaxis, aerotaxis) |
question
| eukaryotic cells |
answer
| mostly larger than prokaryotic cells and usually contain a visible, membrane-bound nucleus |
question
| protozoa |
answer
| are unicellular, generally motile, eukaryotes |
question
| algae |
answer
| eukaryotes, range in size from single cells to giant sea kelp. contain chloroplasts |
question
| fungus |
answer
| absorptive heterotrophs (secrete exoenzymes into the environment and then absorb the digested nutrients). saprophytes/parasites. either yeast/mold. dimorphic- have both. |
question
| stains |
answer
| consist of solvent (water/ethanol) and a colored molecule (chromogen) |
question
| chromophore |
answer
| portion of the chromogen that gives it it's color |
question
| auxochrome |
answer
| charged portion of a chromogen that allows it to act as a dye through ionic or covalent bonds between chromogen and the cell |
question
| basic stains |
answer
| auxochrome becomes positively charged- they are attracted to the negative charges on the surface of most bacterial cells. *methylene blue, crystal violet, and safranin |
question
| heat fixing |
answer
| kills the bacteria, makes them adhere to the slide, and coagulates cytoplasmic proteins to make them more visible |
question
| negative staining |
answer
| used when bacteria are too delicate to withstand heat fixing. used when actual size matters. uses a dry solution where chromogen is acidic and carries a negative charge. negative charge on the bacterial surface repels the negatively charged chromogen, so cell remains unstained against colored background. helpful for visualizing hard to stain microbes. displays capsules- lack a net -/+ charge and impedes stains by neither attracting nor repelling them. |
question
| acid dyes |
answer
| repelled by bacteria because of the negative charges of the chromophores- these leave the cell colorless and color the background instead. *used in negative staining. *congo red, nigrosin, eosine, and acid fuchsin. |
question
1. modified maneval's technique--> employs congo red, a negative dye, to color to background. the cells are then dyed with red with acid fuchsin that has been dissolved in modified maneval's stain. reacting with the acid in maneval's causes congo red to turn sky blue. you observe: pale red cells, clear capsules, against blue background. 2. Gin's method |
answer
| two techniques of capsule staining |
question
| endospore staining |
answer
| detect the presence and location of spores in bacterial cells. endospores are a dormant form of bacterium that allows it to survive poor environmental conditions due to keratin (through outer covering). located centrally, terminally, or subterminally |
question
| flagella staining |
answer
| allows direct observation of flagella. used to distinguish motility.; |
question
| streptococcus/streptobacillius |
answer
| if the cell continues to divide in the same plane and remain attached |
question
| coccobacilli |
answer
| short rods |
question
| diplococci/diplobacilli |
answer
| two microbes together |
question
| tetrads |
answer
| groups of four cocci |
question
| bipolar staining |
answer
| spots of the stain are at the end of the cells |
question
| simple stain |
answer
| prepare by coloring the bacteria with a single, basic dye. |
question
| acid-fast staining |
answer
| works based on composition of cell wall. used to identify mycobacterium. Tb- forms cords. used to detect cells capable of retaining a primary stain when treated with an acid alcohol.. the presence of mycolic acids (waxy substance that gives acid-fast cells a higher affinity for the primary stain and resistance to decolorization by an acid alcohol) in the cell walls of acid-fast organisms |
question
1. primary stain- Ziehlscarbolfuchsin (basic stain) 2. apply heat to fixate 3. rinse off stain 4. apply acid-alcohol (decolorizer) 5. apply counterstain (2nd stain) methylene blue 6. colorless absorbs blue and turns light blue (non-acid fast) and red will not pick up blue (acid-fast) |
answer
| the steps of acid-fast staining |
question
| plasmodium falciparum |
answer
| the most severe protozoan |
question
| sporozoa- plasmaodium |
answer
| leading cause of malaria. asexual stages only found in humans. mosquito-sexual stages of the life cycle. burst out of red blood cells, releasing foreign substances into the bloodstream |
question
| light crystal violet background |
answer
| can see balloon appearance of blood cells bursting on this |
question
| purple |
answer
| gram- positive color |
question
| pink |
answer
| gram- negative color |
question
| gram positive (purple) |
answer
| thick layer of peptidoglycan associated with teichoic acids |
question
| gram- positive (pink) |
answer
| lipoprotein and lipopolysaccharide are found in conjunction with a thin peptidoglycan layer |
question
| differential stain |
answer
| a procedure that distinguishes between various microbes according to their ability to retain certain dyes. |
question
| NOW!! |
answer
| study the procedure to prepare gram-stain!! |
question
| loop-dilution series |
answer
| serial dilution (each tube diluted from the previous tube) |
question
| countable plate |
answer
| has between 30-300 colonies in it |
question
| quebec colony counter |
answer
| a device that holds your petri dish while providing glareless light and variable magnification. |
question
| "NG"- no growth or "TFTC"- too few to count |
answer
| plates with fewer than 30 colonies are marked either what or what? |
question
| small, lenticulate (lens-shaped) colonies |
answer
| grow where bacteria are caught in the agar |
question
| larger, "typical" colonies |
answer
| develop on the surface where they are not confined by medium. |
question
| because they are competing for nutrients |
answer
| why are colonies that are in clusters together smaller? |
question
| Koch's postulates |
answer
| define a procedure that determines which organism causes a specific disease. |
question
| mixed culture |
answer
| by using what kind of culture will you end up with two complete separate cultures? |
question
| aggitate!!! |
answer
| what must you do for pour plate technique? |
question
| streak plate |
answer
| a means of isolation |
question
| streak plate |
answer
| concentration gradient (decreasing quantity) of bacteria across solid medium |
question
| streak plate |
answer
| uses the quadrant method |
question
| spread plate |
answer
| NOT a means of isolation |
question
| spread plate |
answer
| means of manipulating an already isolated bacteria- "lawn" of bacteria |
question
| spread plate |
answer
| used to evaluate sensitivity of bacteria to antibiotics |
question
| invert it so the condensation won't fall onto the medium before it is set |
answer
| what do you do to your spread plate before you incubate it? |
question
| colony |
answer
| a visible clump of growth on the surface of the agar |
question
| confluent growth |
answer
| colonies flowing together |
question
| bacterial growth |
answer
| an increase in population numbers due to binary fission, not size of individual cells |
question
| macconkey's agar |
answer
| used for dip-n-count, it is a selective, differentiable medium for gram-negatives |
question
| dip-n-count |
answer
| what lab test determines if coliforms are present and allows one to differentiate between lactose and non-lactose fermenting gram negative bacilli |
question
| dip-n-count |
answer
| uses lactose broth, macconkey's agar, is made of biosalts and crystal violet. put it in saddle for 30 seconds. |
question
| water analysis |
answer
| used to determine the concentration of aerobic and facultative anaerobic, heterotrophic bacteria in water. to see if water meets standards. |
question
| water analysis |
answer
| look for coliforms. it is positive if it produces gas and bubbles up- turbidity. |
question
| coliforms |
answer
| gram-negative, aerobic or facultative anaerobe, rod-shaped bacterium that ferments lactose |
question
| coliforms |
answer
| indicator organism that shows that fecal contamination of water has occurred. |
question
| serial dilution |
answer
| used to reduce the cell density to achieve countable plates |
question
| membrane-filter technique |
answer
| this technique detects presence of much more abundant coliform such as e.coli or e. argoenes. |
question
| quantitative, confirmed test, completed test, and identification using Enterotube II. |
answer
| study water analysis! |
question
| coagulate test |
answer
| differentiate between s. aureus and other g. positive cocci. produces coagulase enzyme. |
question
| through streak plate isolation and then flooding with iodine |
answer
| how to you see if amylase is produced on starch medium? |
question
| a halo of discoloration around organism |
answer
| what shows that amylase was produced? |
question
| the disk diffusion test |
answer
| what did we use to test disinfectants and antiseptics? |
question
| witch hazel |
answer
| what is NOT an antiseptic? |
question
| measure the diameter of nongrowth to growth |
answer
| how do you measure the results of the disk diffusion test? |
question
| disinfectant |
answer
| antimicrobials that are suitable for nonliving surfaces |
question
| degermination |
answer
| physical removal of germs. reduces the total microbial load. some examples- soap, detergents, alcohol |
question
| antisepsis |
answer
| chemical reduction of microbial load |
question
| multi-test medium (Enterotube II) |
answer
| this medium tests 2 or more independent reactions |
question
| anaerobes |
answer
| only positive rods and positive strains produce what? |
question
| general all purpose bacterial media |
answer
| nutrient agar and nutrient broth are what kind of media? |
question
| liquid form |
answer
| what is the form of nutrient broth? |
question
| pure culture |
answer
| contains only one kind of bacteria |
question
| water, carbon, an energy source, nitrogen, and minerals |
answer
| nutritional requirements of bacteria.. all must have what 5 things? |
