Micro Exam One

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  1. Prokaryote
    unicellular microorganism that lacks a nucleus and membrane-bound organelles; much small than eukaryotes; live everywhere, even in extreme environments; reproduce asexually
  2. Eukaryote
    any organism made up of cells containing a nucleus composed of genetic material surrounded by a distinct membrane
  3. Pathogen
    a microorganism capable of causing disease
  4. Pasteurization
    the use of heat to kill pathogens and reduce the number of spoilage microorganisms in food and beverage
  5. Bioterrorism
    the use of microbes or their toxins to terrorize human populations
  6. Importance of microorganisms to humans, animals, plants, and the environment
    Vaccines/medicines; Fermentation; Decomposition/fertilizer; Algae/Food supply; Digestion; Infections
  7. Antoni van Leeuwenhoek
    observed microbes and introduced most types of microorganisms to the world; "Father of bacteriology and protozoology"
  8. Louis Pasteur
    investigated spontaneous generation which led to scientific method; also developed pasteurization
  9. Robert Koch
    proved that bacteria can cause disease; developed technique of agar colonization; established Koch's Postulates to prove the cause of an infectious disease
  10. Christian Gram
    developed a staining technique to distinguish between different bacteria
  11. Protozoa
    unicellular eukaryotes; nutrition and cell structure similar to animals; liquid habitat; most reproduce asexually, some sexually
  12. Fungi
    eukaryotes; saprophytic (obtain nutrition from dead organisms); rigid cell walls; [molds, yeasts]
  13. Algae
    unicellular or multicellular; photosynthetic; live in fresh and salt water; sexual or asexual reproduction
  14. Germ Theory of Disease
    hypothesis formed by Pasteur that microorganisms are responsible for disease
  15. Koch's Postulates
    • 1. Suspected causative agent must be found in every case and absent from healthy hosts
    • 2. Agent must be isolated and grown outside of the host
    • 3. When introduced to healthy host, host must get disease
    • 4. Same agent must be found in diseased experimental host
  16. Polar covalent bond
    type of bond in which there is unequal sharing of electrons between atoms with opposite electrical charges
  17. Nonpolar covalent bond
    type of chemical bond in which there is equal sharing of electrons between atoms which have similar electronegativities
  18. Ionic bond
    a type of bond formed from the attraction of opposite electric charges; electrons are not shared
  19. Hydrogen bond
    the electrical attraction between a partially charged hydrogen atom and a full or partial negative charge on a different region of the same molecule or another molecule
  20. Acid
    compound that dissociates into one or more hydrogen ions and one or more anions
  21. Base
    molecule that bonds with hydrogen ions when dissolved in water
  22. Salt
    a crystalline compound formed by ionic bonding of metallic with nonmetallic elements
  23. Buffer
    a substance, such as protein, that prevents drastic changes in pH.
  24. pH
    concentration of hydrogen ions in a solution
  25. Functional group
    an arrangement of atoms common to all members of a class of organic molecules
  26. Denaturation
    process by which a protein's 3-D structure is altered, eliminating function
  27. ATP (adenosine triphosphate)
    the primary short-term, recyclable energy molecule feuling cellular reactions
  28. Importance of Hydrogen bonds
    stabilize the 3-D shapes of large molecules which is critical for the functioning of enzymes, antibodies, intercellular chemical messengers, and the recognition of target cells by pathogens; also weak bonds, so they can be overcome easily if necessary
  29. Qualities of water that make it vital to life
    • 1. Water molecules are cohesive, generating surface tension, which allows dissolved material to transport into and out of a cell
    • 2. Water is a solvent, dissolving electrically charged molecules easily
    • 3. Water can remain liquid over a whide range of temperatures
    • 4. Water can absorb significant amounts of heat energy without changing temperature; when heated, molecules evaporate and take much of the energy with them
    • 5. Water molecules participate in many chemical reactions including hydrolysis and dehydration synthesis
  30. Explain why most organisms survive only within a narrow pH range.
    fluctuations outside of these ranges inhibit metabolism and may cause fatalities; too hot = denaturation, too cold = no growth
  31. Biological macromolecules
    • Lipids - fats, phosopholipids, waxes, steroids
    • Carbohydrates - starch, glycogen, glucose, fructose
    • Protein - glycoproteins, lipoproteins, nucleoproteins
    • Nucleic acids - DNA, RNA
  32. Phospholipids
    contain two fatty acid chains and a phophate functional group; "head" of phospholipid is hydrophilic, "tail" is hydrophobic; bilayers compose the outer membranes of all cells and the inner membranes of plant, fungal, and animal cells
  33. Sterols
    steroids with an -OH functional group that interfere with the tight packing of fatty acid chains of phospholipids keeping the membranes fluid and flexible at low temperatures
  34. Roles of carbohydrates
    Large carbs are used for long-term storage of chemical energy, while smaller carbs serve as a ready energy source in most cells; also form part of the DNA and RNA backbones; other carbs are converted into amino acids; polymers of carbs form cell walls and are involved in intercellular interactions between animal cells
  35. Functions of proteins, primary/tertiary levels, denaturation
    Function as structural components, enzymatic catalysts, cell function regulators, substance transporters, and defense/offense mechanisms; primary structure-sequence of amino acids, can vary in length and sequence; tertiary structure-consists of the 3-D shape designed to complete its function; denaturation occurs when the 3-D structure is disrupted by heat, change in pH, or salt concentration
  36. Chemical structure of nucleotides; DNA vs RNA nucleotides
    Nucleotides consist of phosphate, a pentose sugar, and one 5 cyclic ring of nitrogenous bases; DNA=deoxyribose, A,G,C,T, no hydroxyl group; RNA=ribose, A,G,C,U, hydroxyl group
  37. Role of ATP and chemical structure
    Composed of three phosphate groups and is the principle, short-term, recyclable energy supply for cells; when phosphate bonds are broken, energy is released and ATP is converted to ADP; energy from ATP can be used for synthesis reactions, locomotion, and transportation of substances into and out of cells
  38. Capsule
    glycocalyx composed of repeating units of organic chemicals firmly attached to the cell surface
  39. Flagella
    long, whiplike structures protruding from a cell
  40. Fimbriae
    sticky, proteinaceous extensionsof some bacterial cells that function to adhere cells to one another and to environmental surfaces
  41. Pili
    tubules involved in bacterial conjugation
  42. Cell wall
    in most cells, structural boundary composed of polysaccharide or protein chains that provides shape and support against osmotic pressure
  43. Gram-Positive cell
    prokaryotic cell having a thick peptidoglycan wall containing teichoic acids; appears purple in Gram-Stain
  44. Gram-Negative cell
    prokaryotic cell having a wall composed of a thin layer of peptidoglycan, an external membrane, and a perimplasmic space between; appears pink on Gram-stain
  45. Endotoxin
    potentially fatal toxin released from cell wall of dead and dying Gram-negative bacteria
  46. Cytoplasmic membrane
    membrane surrounding all cells and composed of a fluid mosaic of phospholipids and proteins
  47. Osmosis
    diffusion of water molecules across a selectively permeable membrane
  48. Isotonic
    characteristic of a solution having the same concentration of solutes and water as another
  49. Hypertonic
    solution having a higher concentration of solutes than another; causes cells to shrink
  50. Hypotonic
    solution having a lower concentration of solutes than another; causes cells to swell and sometimes burst
  51. Ribosome
    nonmembranous organelle found in prokaryotes and eukaryotes, composed of protein and ribosomal RNA and functions to make polypeptides
  52. Nucleus
    spherical to ovoid membranous organelle containing a eukaryotic cell's primary genetic material
  53. Endoplasmic Reticulum (ER)
    netlike arrangement of hollow tubules continuous with the outer membrane of the nuclear envelope and functioning as a transport system
  54. Golgi body
    in eukaryotic cells, a series of flattened, hollow sacs surrounded by phospholipid bilayers and functioning to package large molecules for export in secretory vesicles
  55. Lysosome
    vesicle in animal cells that contains digestive enzymes
  56. Mitochondria
    spherical to elongated structures found in most eukaryotic cells that produce most of the ATP in the cell
  57. Chloroplast
    light-harvesting organelle found in photosynthetic eukaryotes
  58. Endosymbiotic Theory
    proposal that eukaryotes were formed from the phagocytosis of small prokaryotes by larger prokaryotes, forming organelles
  59. Prokaryotic cells vs. Eukaryotic cells
    • prokaryotes=no membrane-bound organelles, smaller
    • eukaryotes=membrane-bound organelles, larger & more complex
  60. Composition and function of capsules, relevance to human health
    glycocalyx composed of organized repeating units of organic chemicals firmly attached to the cell surface; help protect cells from drying out, may prevent bacteria from being recognized or devoured by defensive cells of the host
  61. Prokaryotic fimbriae and pili vs flagella
    fibriae are stikcy, bristle-like projections that help bacteria stick to one another and substances in the environment; pili mediate the transfer of DNA from one cell to another by conjugation; both are shorter than flagella which functions in locomotion
  62. Cell walls of Gram-positive and negative cells
    Gram-positive bacterial cell walls have a thick layer of peptidoglycan and teichoic acids, a negative charge, and a purple color; gram-negative bacterial cell walls have a thin layer of peptidoglycan, phospholipids, proteins, and lipopolysaccharides, and appear pink
  63. Type of cells that contain endotoxin and location, "toxic" component, clinical syndrome
    found in outer cell wall of Gram-negative cells; toxic component is known as LPS or Lipid A; may cause septic shock
  64. Composition and function of cytoplasmic membrane
    made up of phospholipid bilayer composed of lipids and proteins; selectively permeable, proteins transport substances across it, and it helps maintain a concentration and electrical gradient; in photosynthetic bacteria, also harvests light energy
  65. Osmosis, isotonic, hypertonic, hypotonic solutions and effects on cells
    osmosis is the diffusion of water across a selectively permeable membrane; in isotonic solutions neither side of the membrane will experience a net gain or loss of water, in hypertonic solutions cells will lose water and shrivel, in hypotonic solutions cells will take in water and expand, sometimes causing it to burst in animal cells, however plant and bacterial cells have a cell wall to prevent this
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Micro Exam One
2011-09-29 04:03:49

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