Microbio test 1

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Microbio test 1
2014-09-17 20:37:38
microbio microbiology

first exam cards
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  1. Name
    several specimens that can be collected for culturing microorganisms.  Name and describe the five I’s in order
    for culturing microorganisms in a Microbiology lab.
    • A. environment, air, surfaces, bodily fluids, 
    • B.Inoculation: collecting and securing specimen
    • on medium

    • Incubation: keeping culture at right
    • temp.

    Isolation: separating cultures

    • Inspection: macro and micro looking and
    • testing

    • Identification: testing proves what it
    • is
  2. What
    is a culture?
    The macroscopic evidence of growth on a medium.
  3. Do
    all microorganisms require the same temperature or atmospheric gases for
    incubation?  If not, explain.
    If an org needs room temp that’s wherethey survive, if it needs body  temp tharist wr it thrives
  4. Agar
    A complex polysaccharide isolated from red alga gelidium. used to give solid surface for media.
  5. What
    are the differences between general purpose, enriched, selective, and
    differential media?  Can medium be
    classified as both selective and differential?
    General purpose is for anything

    Enriched has many nutriennts for any growth

    • Selective has things that will kill other things and help
    • other things to select for what you want.

    • Deferential is for being able to tell things apart like by
    • color, size, color change, bubble, precipitation.
    • yes
  6. medai
    • Define
    • reducing medium: Grows
    • anaerobic bacteria
    •  carbohydrate fermentation media: Contains
    • sugars and pH indicators to show fermentation

    •  transport media: Maintains and preserves
    • specimens

    • assay media: Used
    • to test the effectiveness of antimicrobial drugs

    • enumeration media: Used
    • in industrial and environmental microbiology
  7. Name
    and describe the three different methods of isolating bacteria listed in
    your textbook on page 65.  Which
    method is mostly used in a Microbiology lab to isolate bacteria?
    • Streak plate: streaks of liquids from loop sterilized btw each step is streaked across plate
    • loop dilution: liquid agar tubes dilute cells wth series of inoculations so cells have room to grow
    • spread plate: liquid dripped onto dish and spread evenly with hockey stick
  8. What
    microscope(s) use visible light for illumination?
    light flied, dark flied, phase contrast and differential interferrence.
  9. What
    microscope(s) use ultraviolet (UV) rays for illumination?
    florescent and confocal
  10. What
    is the difference between a light and an electron microscope?
    electron transmits thro cell to see organells and viruses.
  11. What
    type of microscope has the greatest total magnification
    atomic force, scanning tunneling
  12. What
    is the difference between positive and negative staining?
    • pos:–Positively charged dye is
    • attracted to negatively charged cell walls
    • Stick to the cell and give it color  

    • neg:Negatively charged dye is repelled
    • by negatively charged bacterial cell walls
    • Produces a dark background around
    • the cells
  13. When do you use basic/cationic and acidic/anionic dyes?  Name examples of basic/cationic dyes.  Name examples of acidic/anionic dyes.
    • for neg stain:
    • acidic eg=india ink
    • for pos:
    • basic= crystal violet, safranin, mythylene blue, carbolfusion, malachite green
  14. What charge does the inside and outside of a bacterial cell possess?  What type of dye is responsible for staining the cell?  What type of dye stains the background and leaves colorless cells?
    • inside=positive
    • outside=neg
    • the neg stain sticks to the out edge of cell creating silhouette a neg photo, pos sticks to cell giving color
  15. What
    is the difference between a simple, differential, and special stain?  Which stain provides more information: simple
    or differential stain?
    • Simple
    • stains
    • Require
    • a single dye
    • Uncomplicated procedure

    • Differential stains
    • Use
    • two differently colored stains to clearly contrast cell types or cell
    • parts
    • Complex staining technique
    • diff is better, special is specifically mad for a purpose
  16. Which four structures
    are required for a prokaryotic cell?
    cell membrane, cytoplasm, ribosomes, chromosomes
  17. Name the
    three main morphological shapes of a prokaryotic cell.  Name the most common bacterial cell
    arrangements.  What is pleomorphism?
    • Coccol spheres form diplococc, tetrads,clusters=staphlococc,
    • chains=strephlococc. Sarcina=16

    bacillus rods, form chains,

    spinous: branching filimants.

    • Pleo= variation in shaoe and size btw
    • same species of cell.
  18. Which
    structures for a prokaryotic cell are considered to be external appendages?
    • Flagella,
    • cilia, glyoclayx, pseudopods, axil filaments
  19. What
    is the structure and function of a prokaryotic flagellum?  Describe the three parts of the flagellum
    the wiggly tail spins like a chork screw to move the cell, the basal body, the hook, and the flament
  20. Name
    and describe the different arrangements for prokaryotic flagella
    • Monotrichous: single flag, lophotrichous:tuffs,
    • amphitrichous: on the poles of both ends, peritrichous:all around randomly
  21. What is chemotaxis?  What is the difference between positive
    and negative chemotaxis?
    Responce w/ movement to or away from chem stimu,pos=towards neg=away
  22. What is the
    structure and function of axial filaments (also known as periplasmic
    Two or more long coiled threads found in spirochetes. Internal flagellum enclosed between the cell wall and cell membrane. Impart a twisting or flexing motion to the cell.
  23. What is the
    structure and function of prokaryotic fimbriae?
    • •provide
    • adhesion but not locomotion
    • •Small,
    • bristle-like fibers sprouting off the surface of certain species of bacteria
  24. What is the
    structure and function of prokaryotic pili?
    • •sex
    • pilus

    • Long, rigid tubular structure made of pilin protein
    • Only found in Gram-negative bacteria
    • Used in conjugation, the partial transfer of DNA from one cell to another. Production
    • of pili is controlled genetically
  25. Name and
    describe the different types of the prokaryotic glycocalyx.
    • •Slime layer
    • Forms loosely around the cell
    • Protects the cell from loss of
    • water and nutrients
    • •Capsule
    • More tightly bound to a cell than a
    • slime layer
    • Denser and thicker than a slime layer
    • Formed by pathogenic bacteria
    • Protect bacteria against phagocytic white blood cells
  26. What
    is the composition of the cell wall for a prokaryotic cell?  Do all prokaryotic cells possess a cell
    wall?  Name all of the differences
    between Gram-positive and Gram-negative cells
    • Peptidoglycan,
    • neg has two layers: thick cell wall and cyto membrane, pos has three: thin cell wall, outer membrane, cyto membrane.
  27. Name
    the primary dye, mordant, decolorizer, and counterstain for the Gram stain.
    • The primary dye is crystal violet, the mordant is Gram’s iodine, the decolorizer is
    • alcohol rinse, red dye safranin is the counter stain.
  28. What
    structural composition is responsible for Gram-positive and Gram-negative cells
    staining different colors in the Gram stain?
    the results differ bc of the dif cell walls and how they react to the series of reagents.
  29. What
    color do Gram-positive and Gram-negative organisms appear under the microscope?
    • gram pos is violet
    • gram neg is red
  30. What structural composition is responsible for acid-Fast positive and acid-Fast
    negative cells staining different colors in the Ziehl-Neelsen acid-fast stain?
    • •Mycolic acid
    • Found in the cell walls of Mycobacterium and Nocardia. Very-long-chain fatty acid. Contributes to pathogenicity of these organisms
  31. What
    is the Gram reaction and morphology for Escherichia
    coli and Staphylococcus aureus?
    • e.coli= gram neg rods
    • staph= gram pos cocci
  32. Name the two genera that possess this unique
    mycobacterium and nocardia
  33. Name the primary dye, mordant, decolorizer, and counterstain for the Ziehl-Neelsen acid-fast stain.  What color do acid-fast positive
    and acid-fast negative organisms appear under the microscope?
    • primary:Carbolfuchsin
    • mordant:carbolic acid (phenol)
    • counterstain:Methylene blue
    • decolorizer:Acid-alcohol
    • pos:red
    • neg:blue
  34. What is unique regarding the genus Mycoplasma?
    naturally lack cell wall
  35. What
    is the structure and function of the Gram-negative outer membrane?
    • •Contains
    • specialized polysaccharides and proteins
    • –Lipopolysaccharide
    • •Polysaccharide
    • chains function as antigens and receptors
    • •Endotoxin:  stimulates fever and shock reactions
    • –Lipoproteins:  anchor the outer membrane to peptidoglycan
  36. What is the structure and function of
    the prokaryotic cell membrane?  Do all
    prokaryotic cells possess a cell membrane?
    • •Lipid bilayer embedded with proteins
    • completely around the cytoplasm
    • •Mycoplasma contain
    • high amounts of sterols
    • •Archaea contain unique branched hydrocarbons rather than fatty acids
    • •Energy reactions, nutrient processing, and synthesis
    • •Transport
    • •Selectivenpermeability
    • •Secretion