Micro Midterm PDF

What are the 5 I\'s? Inoculation Incubation Isolation Inspection Identification What is streaking for isolation? This technique useful for separating out individual species in a mixed culture What are the steps for streaking for isolation? -Insulate loop -pick up mix culture and start stre...

What are the 5 I\'s? Inoculation Incubation Isolation Inspection Identification What is streaking for isolation? This technique useful for separating out individual species in a mixed culture What are the steps for streaking for isolation? -Insulate loop -pick up mix culture and start streaking quadrant 1 -repeat streaking for 2 and 3 without picking up new media What must you do to the loop before moving onto the new quadrant? sterilize it What is a broth? liquid media on which bacteria grow What is agar? Solid media on which bacteria grow What is general media? where most things grow, ex. nutrient broth or agar What is differential media? allows growth of several types of microbes and displays visible differences among those micro What is a selective media? contains one or more agents that inhibit growth of some microbes and encourage growth of the desired microbes What is an example of a general media? NA What is an example of a differential media? blood agar , MAC , MSA What is an example of a selective media? MSA and MAC What is an optical microscope? microscope that uses light to form an image What is an electron microscope? A microscope that uses magnets to aim a beam of electrons at a cell to produce an image. This microscope magnifies images up to 500,000 times the actual size. What is a scanning probe microscope? allows us to observe a single atom What color is gram positive? blue/purple What color is gram negative? pink/red What is gram staining? Gram staining is a procedure by which bacteria can be classified by the ability of the cell wall to absorb a crystal violet dye, followed by a red safranin counterstain. What are the steps of gram staining? 1\. place a drop water on slide and smear the bacteria 2\. Heat fix or air dry 3\. Crystal violet for 30 secs 4\. Wash off 5\. Iodine for 30-40secs 6\. Wash off 7\. Decolorize with 95% alcohol at a 45-degree angle until dry 8\. Wash off 9\. Safranin for 1 min 10\. Blot dries on paper 11\. Inspect/Identify How long do you leave the slide into the crystal violet? 30 seconds How long do you leave the slide in the iodine? 30-40 seconds How long do you leave the slide in the safranin? 1 minute What is the primary stain in a gram stain? crystal violet What is the mordant in the gram stain? Iodine What is the decolorizer in the gram stain? 95% ethanol What is the counterstain in the gram stain? safranin What are the shapes of bacteria? bacilli, cocci, spirilla What is a diplo arrangement? pairs of bacteria What is strepto arrangement? chains of bacteria What is staphylo arrangement? grape-like clusters of bacteria What is a tetrad arrangement? 4 pair of bacteria ( 2 on top of each other ) What is a pallisade arrangement? 3 or more bacteria stacked on top of each other What is a sarcina arrangement? cube of cocci What is glucose test? Differentiates between glucose fermenters and non-glucose fermenters What does the color change indicate in a glucose test? As the pH drops, the pH indicator changes color, often turning yellow. This results in a positive test What is the bile esculin test? determines ability of organism to hydrolyze esculin to glucose and esculetin; released esculetin reacts with ferric ion, causing diffuse blackening on medium. black = positive for esculin hydrolyzation What color is a positive bile esculin test? black What is the catalase test? This test detects the presence of catalase. To perform this test, an inoculated loop takes a small amount of a colony and puts it on a slide. Then, one to two drops of hydrogen peroxide is added. If there are bubbles then catalase is present because catalase breaks down hydrogen peroxide into water and gas. If catalase is not present, then nothing happens What is a positive catalase test? bubbles What is a negative catalase test? no bubbles What is blood agar used for? determines hemolytic reactions What is beta hemolysis? Complete= clear ring What is alpha hemolysis? Partial hemolysis= green ring What is gamma hemolysis? no hemolysis What is a coagulase test? Tests for the conversion of fibrinogen to fibrin, which walls bacteria from immune response What is a positive coagulase test ? solid (clot formation) What is a negative coagulase test? no clot formation (liquid) What is thioglycollate broth used for? Used to determine the oxygen requirements of bacteria What is an aerobe? any organism that requires oxygen What is an obligate Anaerobe? cannot grow in the presence of oxygen What is an facultative anaerobe? can grow with or without oxygen What is an aerotolerant anaerobe? Can only grow in the absence of oxygen but will tolerate the presence of oxygen What is an microaerophile? Require atmospheric oxygen just at low levels How can we determine if a microbe is antibiotic susceptible? If it has a zone of inhibition (clear zone). How can we determine if a microbe is antibiotic resistant? if it has no zone of inhibition What is a parfocal microscope? The lens stays in focus when magnification is changed What is paracentric? Objects placed in the exact center of the viewing field using one objective will still be centered after changing to another objective. Add or remove terms You can also click the terms or definitions to blur or reve