Quiz 3-Micro Exam 1

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Quiz 3-Micro Exam 1
2012-09-24 21:32:02

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  1. What do most organisms use for energy?
    CHO catabolism
  2. What happens to pyruvate after glycolysis?
    • Aerobic Respiration - 02 present
    • Fermentation (anaerobic, O2 inhibits)
  3. What cofactor is required for glycolysis?
  4. What is Glycolysis?
    • Catabolizes glucose to 2 pyruvates
    • Universal pathway in cytoplasm
    • No O2 requirement, nets 2 ATPs/glucose
    • Requires NAD+ electron carrier as cofactor
  5. What is nicotinamide?
    NADH or NAD
  6. What is the fate of pyruvate if conditions are anaerobic?
    • No O2
    • Aerobic respiration does not occur so glycolysis is only source of ATP and MUST CONTINUE
  7. What is critical for gylcolysis to occur?
    Oxidize NADH to NAD+, results from fermentation
  8. What is fermentation?
    • Always occurs anaerobically
    • Reduces pyruvate, oxidizes NADH to NAD+
    • Fermentation end products produced as a result
  9. What are the two types of fermentation?
    • Lactic Acid Fermentation
    • Alcoholic Fermentation
  10. What is Lactic Acid Fermentation?
    • Pyruvate reduced directly to lactic acid
    • Acid denatures (curdles) milk protein, flavors 'clutured' dairy products
  11. What is alcoholic fermentation?
    • Mainly by yeast
    • Pryuvate decarboxylation + reduction to CO2 and ethanol (alcohol, leaven bread, fuel)
  12. What are some food produced during bacterial fermentation?
    Vinegar, sauerkraut, pickling, soy sauce, other products
  13. What happens on the molecular level during lactic acid fermentation?
    Pryuvic Acid to Lactic Acid (Reduced NADH to Oxidized NAD+)
  14. What happens on the molecular level during alcohol fermentation?
    • Pyruvic Acid to Carbon Dioxide + acetaldehyde (via decarboxalation)
    • Acetaldeyhde to ethyl alcohol (NADH to NAD+)
  15. What bacteria MUST use O2?
    • Obligate/strict aerobes
    • Aerobic Respiration only
  16. What type of bacteria MUST NOT use O2?
    • Strict Anaerobes
    • Fermentation Only
  17. What type of bacteria will use O2 if present but can also ferment without O2?
    Facultative Anaerobes
  18. What is the energy yield during Aerobic Respiration?
    • Faster Growth
    • Yields 36-38 ATPs/glucose
  19. What is the energy yield during Anaerobic Respiration?
    • Growth is Slow
    • Yields 2 ATP/glucose
  20. What is happening on the molecular level during aerobic respiration?
    Acetyl-CoA is produced by decarboxylation and oxidation of pyruvate
  21. What occurs during the Kreb Cycle? Location?
    • Acetyl-CoA 2 carbon units oxidized
    • In prokaryote cytoplasm
    • Generates critical reducing potential (NADH, FADH2) also CO2 and some ATP
  22. What is the Electron Transport Chain? Where is it located?
    • Located in the Cell Membrane
    • NADH, FADH2, passes electrons via carriers to O2
    • H+ pumping creates proton gradient
  23. What is Oxidative Phosphorylation?
    Proton gradient drives ATP synthesis by ATP synthase
  24. What are the oxygen conditions during Glycolysis?
    Anaerobic, O is not required; does not stop however if O is present
  25. What is the starting and ending material for the Kreb Cycle?
    • 2 pyruvic Acid/6 CO2, 8 NADH, and 2 FADH
    • 2 ATP produced
  26. What are the staring and molecules for the Electron Transport Chain?
    • 6 O2/6 H2O
    • 34 ATP produced
  27. What are the starting and ending molecules for glycolysis?
    • 1 glucose/2 pyruvic acid and 2 NADH
    • 4 ATP, (2 Net)
  28. What is the breakdown of ATP production during Aerobic conditions?
    • Glycolysis 10
    • Pyrvuate 6
    • Kreb Cycle 24
    • Less E for Phosphorylation -2
  29. What is the breakdown of ATP production during Aerobic conditions?
    • Glycolysis 4
    • Less E for Phosphorylation -2
  30. How do lipids and proteins enter metabolic pathways to produce energy?
    • Fats - beta oxidation - Kreb - ETC - ATP
    • Proteins - AA - AA Catabolism - Kreb - ETC
  31. How does Prokayotic cell division occur?
    Binary Fission
  32. What occurs during binary fission?
    • DNA replication
    • Mother cell divides to form 2 daughter cells
  33. What is the process of cell division in prokayotic cells?
    • No cycle Cycle
    • Nucleotide divides; cell wall and membrane begin to form transverse septum
    • Transverse septum becomes complete
    • Daughter Cells seperate
  34. What occurs during each phase of the Bacterial Growth Curve?
    • Lag Phase (few mins) - Cell division, increased metabolism
    • Log Phase - Exponential Growth, Highest metabolism, shortest generation time, MOST SENSITIVE to DAMAGE
    • Stationary Phase - Nutrients decline, wastes increase, pH changes
    • Death or Decline Phase - Nutrients depleted, wastes toxic, exponential death. Sporulation of possible
  35. What are the PHYSICAL bacterial growth factors?
    Temperature, pH, and Osmotic Pressure
  36. What are the effects of temp on bacterial growth factors?
    • Affect on enzyme activity
    • Each species has minimum, optimal, and max. temp.
  37. What is a psychrophile?
    Cold-loving (water, soil, fridge)
  38. What is a mesophile?
    25-40 C, includes most pathogens, spoilage bacteria
  39. What is a Thermophile?
    • Heat-loving, 50-60 C
    • Hot Springs
  40. What is an Extreme Thermophiles?
    • Deep Sea Vens
    • Eg - Archaeabacteria (some thrive at 115 C)
  41. What is an acidophile?
    grow below pH 5.5
  42. What is a Neutrophiles?
    • pH 5.5-5.8
    • Includes most pathogens (pH 6.5-7.5)
  43. What are Alkaliphiles?
    Prefer pH 8-12
  44. What occurs in a HYPOTONIC environment?
    Cells Swell
  45. What occurs in a HYPERTONIC environment?
    • Cause cell shrinkage (plasmolysis), inhibit growth
    • Jam
  46. What are Halophiles?
    Require HIGH salt
  47. What are extreme halophiles?
    Thrive at 20-30% Salt
  48. What are the are the chemical factors that alter microbial growth?
    • Carbon
    • Oxygen: Potential poison, but required by many organisms
    • Nitrogen
  49. What are superoxide anions (O2-)?
    Formed when growth in O2 environments results in oxidative rxns, toxic
  50. What are superoxide anions (o2-) detoxified?
    • Superoxide dismutase
    • (SOD) + Catalase (CAT) enzymes
  51. What are the requirements of Obligate aerobes?
    O2 required, no fermentation enzymes (SOD+, CAT+)
  52. What are the requirements of Obligate Anaerobes?
    O2 is toxic (SOD-, CAT-)
  53. What are the requirements of facultative anaerobes?
    Use of O2, but can ferment (SOD+, CAT+)
  54. What are the requirements for Microaerophiles?
    Grow only at low [o2] (SOD+, CAT-)
  55. What is the role of Nitrogen in Microbial Growth?
    • AA, Nucleotides
    • Nitrogen-fixing Bacteria
    • N2 gas into NH3, which is then accessible to other organisms
  56. What are Fatidious microbes?
    • Difficult to grow due to complex nutritional needs
    • Usually due to absence of enzymes required for synthesis of nutrients
  57. What is sterilization?
    Removes/kills ALL microbes, absolute (autoclave)
  58. Commercial sterilization?
    Destroys C. botulinum endospores
  59. Disinfection?
    Reduces number of potentially pathogenic microbes
  60. What is an anticeptic?
    Disinfects living tissue
  61. When are disinfectants used?
    Non-living objects
  62. What are the mechanisms of chemical agent action?
    • Protein denaturation
    • Membrane solubilization/destruction
    • Alkylating agents
  63. What are Alkylating agents?
    CH3 (alkyl) groups, disrupts cell structures, cause mutations
  64. What factors influence anti-microbial effectiveness?
    • Number if microbes, exposure time
    • Microbial Characterisitcs (endospores)
    • Environmental Influences (temp, deactivates when organic material is used)
    • Bacericidal vs Bacteristatic agent used
  65. What are antimicrobial agents?
    • Surfactants: (soaps and detergents) aide removal and not bactericidal
    • Alcohol: (70% in H2O) denatures proteins, dissolves membranes
    • Heavy Metals: Bind/deature proteins
    • Halogens: oxidize, denature proteins
    • Alkylating Agents: Denature proteins, disrupt nucleic acids. Formaldehyde, ethylene oxide (sterilizes)
  66. What are some physical antimicrobials?
    • Heat: Moist is better that dry heat (autoclave)
    • Pasteurization: Kills pathogens in liquid, specific temp for a specific amount of time, NOT sterilization
    • Radiation: (ionizing high energy), Common for heat sensitive products
    • Filtration: (of liquids or air), Membrane pore size excludes microbes