Microbiology Exam #1

  1. Microorganisms include what?
    • Algae
    • Archaea
    • Bacteria
    • Fungi
    • Helminths
    • Protozoa
    • Viruses
  2. Microorganisms... or...
  3. Disease causing organisms
  4. How long after the first bacteria was seen did it take to prove microbes caused disease?
    200 years
  5. What are the characteristics of Protozoa?
    • Protist
    • Eukaryotic
    • Unicellular
    • No cell walls (usually)
  6. What do Helminths include?
    • Roundworms
    • Tapeworms
    • Flukes
  7. What are B Vitamins essential for?
  8. What is important about industrial microbes?
    Man has harnessed them to produce useful things
  9. How many species have been identified on Earth?
    1.8 Million
  10. Van Leeuwenhoek is often called what?
    The Father of Microbiology
  11. What do Medical Microbes do?
    • Protect Health
    • or
    • Cause Disease
  12. What do our normal microbiota include?
    Microbes, mostly bacteria, that live in or on us pemanently
  13. Protists are what?
    A grab bag of species that don't belong to other eukaryotic kingdoms
  14. What ar some characteristics of Fungi?
    • Eukaryotic
    • Cell Walls
    • Contain Chitin
  15. Most microbes on Earth are what?
  16. What are major groups of Fungi?
    • Yeasts
    • Molds
    • Mushrooms
  17. The study of Viruses
  18. What do our normal microbiota do?
    • Crowd out pathogens
    • Produce acids
    • Produce vitamins
  19. How many species of bacteria are there?
  20. There are less species of what?
  21. First living microbes were observed when?
  22. How small are microbes?
    Too small to be seen with the naked eye
  23. Species in domain Eukarya can be assigned to one of what 4 kingdoms?
    • Plantae
    • Animalia
    • Fungi
    • Protista
  24. Molds & Mushrooms are what?
    Yeasts are what?
    • Multicellular
    • Unicellular
  25. What do industrial microbes do?
    Produce chemicals (citric acid), Foods (bread, yogurt), Medical Products (insulin, antibiotics)
  26. Vitamins we absorb are produced by what?
    Intestinal Bacteria
  27. What vitamins are produced by intestinal bacteria?
    • Vitamin K
    • Several B Vitamins
  28. Study of parasites
  29. What are the characteristics of Archaea?
    • Prokaryotic
    • Unicellular
    • No Peptidoglycan in cell walls
  30. Parisitologists usually study what?
    • Helminths
    • Parasitic Protozoa
  31. What do photosynthetic microbes include?
    • Algae
    • Photosynthetic Bacteria
  32. What are the characteristics of Helminths?
    • Eukaryotic
    • Multicellular
    • no cell walls
    • not microscopic
  33. What are major groups of protists?
    • algae
    • protozoa
  34. What is Vitamin K necessary for?
    Blood Clotting
  35. What are the characteristics of Bacteria?
    • Prokaryotic
    • Unicellular
    • Cell Walls with Peptidoglycan
  36. What are the characteristics of Algae?
    • Protist
    • Eukaryotic
    • Unicellular
    • Cell Walls have Cellulose
    • Photosynthetic
  37. What are major groups of Anamilia?
  38. Study of Bacteria
  39. What are environmental microbes?
    • Saprophyte
    • Photosynthetic Microbes
  40. What are the 4 most abundant elements in living organisms?
    Hydrogen, Carbon, Nitrogen, Oxygen
  41. What percent of weight is made up by the 4 elements in living organisms?
  42. What element is the single most abundant by weight in living organisms?
  43. When do molecules form?
    atoms become held together by chemical bonds
  44. Chemical bonds can be... ?... or ?...
    • Covalent (share e-)
    • Ionic (opposite charges)
  45. Weak, temporary bonds
    hydrogen bonds
  46. Why is water a good solvent?
    Forms plentiful hydrogen bonds
  47. What helps DNA and proteins keep their shape?
    hydrogen bonds
  48. Ph is used to indicate what?
    How much hydrogen there is in a solution
  49. Increasing H+ ...
    lower pH
  50. Acidic solutions have... ?
    Basic... ?
    • Higher H+ concentration
    • Lower H+ concentration
  51. Important for structure and used as energy sources?
  52. Carbohydrates can be... ?
    • Monosaccharides
    • Disaccharides
    • Polysaccharides
  53. Chitin is what?
    Polymer of modified glucoses
  54. Glucose can be used as what by nearly all organisms?
  55. Hydrophobic
  56. The breakdown of glucose releases energy that can be recaptured to form...
  57. Breaking the bonds in ATP provides energy for what?
    Numerous cellular activites & chemical reactions
  58. Includes fats/oils, sterols, phospholipids
  59. Broad, fat lipids found in cell membranes to help stabilize it
  60. Who observed the first microbe?
    Van Leewenhoek
  61. Where do saprophytes get their nutrients?
    dead and decaying material
  62. Where do parasites get their nutrients?
    living hosts
  63. What are ions?
    • charged atoms
    • simple compounds
  64. Number of protons determine what?
    the element
  65. The number of neutrons determine what?
    the isotope
  66. What do electrons deermine?
    the chemical properties of an atom
  67. What part of an atom takes part in a chemical reaction?
  68. What do environmental microbes do?
    • Decompose organic waste
    • Produce oxygen
  69. Study of Fungi
  70. Each microorganism has what?
    Genus & species name
  71. All species on Earth belong to one of what three domains?
    • Bacteria
    • Archaea
    • Eukarya
  72. What species are prokaryotic?
    • Bacteria & Archaea
    • Eukarya
  73. How many elements are required by living organisms?
    about 26
  74. Major sterol in the cell membranes of animals
  75. Major sterol in the cell membranes of fungi
  76. What species cell membranes do not have sterol?
  77. What proteins are important in metabolism?
  78. Why are proteins important?
    • Metabolism (enzymes)
    • Transport (nutrients across membrane)
    • Movement (flagella)
  79. What are proteins?
    Polymers of amino acids
  80. What is the covalent bond that holds amino acids together?
    peptide bonds
  81. How many amino acids are found naturally in living organisms?
  82. The 3D shape of proteins is essential for what?
  83. What is denaturation caused by?
    • excess heat
    • acid
    • salts
  84. What does denaturation cause?
    • loss of funcion
    • 3D shape is lost
  85. What are nucleic acids?
    polymers of nucleotides
  86. What forms the backbone in DNA & RNA?
    Sugar and Phosphate
  87. Where does the base of a protein point?
    Away from the strand
  88. Bases of DNA?
    • Adenine
    • Thymine
    • Cytosine
    • Guanine

  89. What does DNA do?
    • Carries info to make protein & carries cells genetic info
    • Assists making proteins
  90. What holds together the strands of DNA?
    hydrogen bonds
  91. ATP
    adenine triphosphate
  92. ATP is converted to ADP which...
    releases energy
  93. What is ATP?
    energy provider in cells of all organisms
  94. Where is ATP produced in Eukaryotes?
    • Mitochondria
    • Cell Membrane
  95. Total Magnification
    obj. lens x ocu. lens
  96. What is resolution?
    ability to see small details
  97. What are fluorescent microscopes used for?
    Quickly identify microbes in complex samples (like clinical specimens)
  98. What is a negative stain?
    Stains slide and not capsule - the unstained spheres will indicate presence of capsule
  99. How are specimens prepared for a scanning electron microscope?
    coated with a heavy metal
  100. Why is an acid-fast stain good for mycobacterium?
    mycobacterium have a think waxy layer, mycolic acid, that resist penetration
  101. How can capsules be seen?
    using a negative stain
  102. One species of mycobacterium causes tuberculosis the other causes what?
  103. Magnets are used as what to direct the beam of electrons?
  104. How does an electron microscope work?
    uses electrons instead of light to illuminate the object
  105. Why is oil immersion used?
    because light refracts when it exits slide and misses small lens
  106. When is a darkfield microscope useful?
    when cells are alive or unstained
  107. What does immersion oil do?
    keeps light from refracting
  108. Why are light microscopes used?
    illuminate specimen
  109. What makes the difference in Gram + and Gram - ?
    thick layer of peptidoglycan makes it hard to remove crystal violet
  110. An acid-fast stain is good for what species?
  111. In-phase light appears...?
    • Brighter
    • Darker
  112. When it comes to finer detail a phase-contrast microscope is better than what?
  113. What is the magnification of a transmissioin electron microscope?
    10,000 - 100,000x
  114. What kind of specimens must be used for a scanning electron microscope?
    whole specimens
  115. Electron microscope images are what color?
    black/white ... color is added by computer software
  116. What gives better resolution?
    shorter wavelengths of light
  117. Why is it difficult to use unstained specimens on a brightview microscope?
    Bright background and almost clear cell
  118. What is the field of view on a brightfield microscope?
    • light
    • dark
  119. What is the limit of magnification on light microscopes?
  120. What is the magnification on a scanning electron microscope?
    1,000 - 10,000x
  121. Short wavelengths of electrons give what in electron microscopes?
    • higher magnification
    • better resolution
  122. What kinds of specimens are used in transmission electron microscopes?
    ultrathin sections
  123. What is a specimen that would be viewed under a fluorescent microscope?
    Mycrobacterium tuberculosis
  124. How does a scanning electron microscope work?
    beams of electron scan specimen surface and light reflects around it
  125. Why are endospores very tough survival structures?
    they resist penetration by stain so heat loosens coat and allows stain to enter
  126. How do electron microscopes work?
    electron sensors detect electron patterns and put image on a screen
  127. What does a phase-contrast microscope do?
    shows differences in phase of light going through specimen
  128. What is a capsule?
    slimy layer of polysaccharides that surrounds cells of some bacteria
  129. Flagella is coated with what and why?
    mordant - they are usually too thin to be seen with a light microscope and mordant thickens it enough to be seen
  130. In fluorescence microscopes cells are stained with what?
    fluorescent dye
  131. What does an endospore stain require?
    heat to drive stain into endospore
  132. How do transmission electron microscopes work?
    electrons pass through specimen and allows internal view of structure
  133. How do Gram Stains work?
    use multiple stains so different cells appear differently at the end
  134. How does the Gram Stain process work?
    • Crystal Violet enters cells
    • Iodine enters cells and binds to crystal violet
    • Alcohol enters and removes crystal violet
    • Safrinin stains rest of cells
  135. Phase-contrast microscope increases... ?
    • contrast
    • detail
  136. Gram Stains use what 4 stains?
    • primary
    • mordant
    • decolorizer
    • counterstain
  137. A Gram Stain is what kind of stain?
    a differential stain
  138. What is done to the specimen for a transmission electron microscope?
    strained with a heavy metal to make it more dense
  139. What is the resolution limit on light microscopes?
    0.2 micrometers
  140. What size are most bacterial cells?
    1-8 micrometers
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Microbiology Exam #1