Microbiology Exam 1

  1. Eukaryotic Cell
    • Cell with a "true" (i.e., membrane bound) "kernel," that is, nucleus and other organelles that are surrounded by membranes
    • Includes Animal and Plant Cells
  2. Prokaryotic Cell
    • Cell that lacks a true nucleus (pro=before/karyon=kernel)
    • Includes Bacteria
  3. Taxonomy: order of classification from least to most specific
    • Domain
    • Kingdom
    • Phylum
    • Class
    • Order
    • Famil
    • Genus
    • Species
  4. Prokaryotic Domains
    • Bacteria
    • Archaea
  5. 3 Domains of Living Organisms
    • Bacteria (Eubacteria)
    • Archaea
    • Eukarya
  6. How many micrometers are in one millimeter?
  7. Approximate size of mitochondiron
    1 micrometer
  8. Size of Smallest Eukaryotic Cell
    10 micrometers
  9. Resolution of Unaided Eye
    200 micrometers
  10. Resolution of Light Microscope
    0.2 micrometer
  11. Average Size of Bacteria
    1-10 micrometer
  12. Average Size of a Virus
    10-100 nanometers (0.01-0.1 micrometers)
  13. Size of Wavelength of Light
    • 400-800 nm (0.4-0.8 mcm)
    • (Thus, this is the limiting factor for light microscopes)
  14. Atom Image Upload 1 Protein Image Upload 2 Ribosome Image Upload 3 Virus Image Upload 4 Bacterium Image Upload 5 Mitochondria Image Upload 6 RBC Image Upload 7 Protozoa
    Order from smallest to largest
  15. Function of Ribosomes
    Make Proteins
  16. Function of Mitochondria
    Make ATP
  18. German Physician from 1800s who defined procedure for determining the microorganism which caused a given disease
    Robert Koch
  19. Developed by Robert Koch to better facilitate generation of pure cultures (improvement over broth)
    Solidified Media
  20. Solidified media (developed by Koch) allowed for this new and simpler procedure for culturing PURE bacterial colonies
    Streaking for Isolation
  21. Koch's procedure for isolating a disease causing microorganism
    • 1. Identify and obtain PURE bacterial culture from infected organism
    • 2. Infect healthy animals with this microbe
    • 3. Establish the same illness in previously healthy animals
    • 4. identify the same microbe in these new animals
    • 5. This organism must be present in every case of the disease
  22. Streaking for Isolation
    • Streak mixed culture across a solidified media
    • Each colony created is assumed to develop from an individual bacterium
    • Transferring a bacterium from this colony to a new plate will then produce a PURE bacteria
    • (In practice, this takes several repeats to isolate a PURE culture)
  23. Why is Escherichia Coli unsuitable for isolation using Koch's Postulates?
    It is part of the normal flora of the GI tract (it can move to the urinary tract and cause a UTI)
  24. Why is Hepatitis D not suitable for isolation using Koch's method
    Hepatitis D can only be pathogenic in the presence of Hepatitis B (thus it does not cause disease in isolation)
  25. Why is Plasmodium Malariae not isolated using Koch's method?
    The lifecycle is too complex:  part of its development occurs in the human host, while another part occurs in the anopheles mosquito
  26. Koch's Postulates
    • 1. The pathogen must be able to infect a non-human host
    • 2. We must be able to culture the pathogen
    • 3. Pathogen must not be part of the normal flora
    • 4. The disease must result from a single pathogen
    • 5. The pathogen must not require specialized environmental influences
    • 6. The pathogen must have a relatively simple life cycle
  27. Why do Koch's Postulates prevent the isolation of HIV/AIDS
    HIV/AIDS can infect a chimpanzee, but the virus does not advance the same way and the chimp does not get sick the way humans do
  28. Obtain ENERGY from sunlight
  29. Obtain ENERGY from chemicals (use oxidation reduction reactions
  30. Obtain ENERGY from organic compounds (e.g. glucose)
  31. Obtain ENERGY from inorganic substances (e.g. sulfur, ammonia, hydrogen)
  32. Two forms of Chemotrophs
    • Organotroph
    • Lithotroph "rock eaters"
  33. Obtain CARBON from CO2
  34. Obtain CARBON from organic compounds
    Heterotrophs ("other feeders")
  35. Obtain ENERGY from sunlight & CARBON from CO2
  36. Obtain ENERGY from chemicals & CARBON from CO2
  37. Obtain ENERGY from sunlight & CARBON from organic compounds
  38. Obtain ENERGY from chemicals & CARBON from organic compounds
  39. Microbes which require O2
    obligate Aerobes
  40. Microbes killed by O2
    Obligate Anaerobes--lack the enzymes required to deal w/O2 metabolites (i.e. toxins)
  41. Microbes which are not killed by O2, but do not use aerobic metabolism (do not require O2 for energy metabolism)
    Aerotolerant Anaerobes
  42. Work best in a low O2 environment (i.e. 2-10%)
  43. Organisms which do not require O2 for metabolism (i.e. may also use anaerobic respiration or fermentation)
    Facultative Anaerobes
  44. What type of respiration uses oxygen as the final electron receptor in the electron transport system
    Aerobic Respiration
  45. What type of respiration uses a compound other than oxygen as the terminal electron receptor in the electron transport system
    Anaerobic Respiration
  46. Which type of organisms use glucose (or other organic molecules such as fats/proteins) as a source of electrons for energy metabolism
  47. Which type of organisms use inorganic compounds (e.g. elemental sulfur, ammonia, hydrogen) as the source of electrons from energy metabolism
  48. What are the possible terminal electron receptors in the electron transport chain
    • Oxygen
    • Nitrate
    • Sulfate
    • Carbonate
  49. What are the various electron donors for the ETC?
    • Sulfur
    • Ammonia
    • Hydrogen
  50. What is the CARBON source for humans?
    • Sugars
    • Humans are heterotrophs
  51. What is the ENERGY source for humans?
    • Sugars
    • Humans are chemotrophs
  52. What type of metabolism does Escherichia Coli implement
    Facultative Anaerobe
  53. List of Environmental Variants
    • Nutrients
    • Carbon Source
    • Sunlight
    • Temperature
    • Temperature Cycling
    • pH
    • Substrate Concentration
    • Source of Cellular Components:  N, S, O2, P, Na, K
    • Pressure
    • Partial Pressure of Gasses
    • Osmotic Pressure
    • Space Availability
    • Pollutants/Toxins
    • Presence of Other Organisms:  competitors, predators, prey, hosts, symbionts
  54. These "cold loving" organisms (e.g. lysteria) grow best below 15Image Upload 8C
  55. These organisms (e.g. Escherichia Coli) grow best b/w 20-40Image Upload 9C
  56. These organisms grow best above 45Image Upload 10C
  57. These organisms are capable of growing in temperatures as high as 121Image Upload 11C (in an environment where the pressure prevents boiling)
    Hyperthermophiles (the actual temperature is still being researched/debated)
  58. These organisms normally live as mesophiles but can withstand short periods of high temperatures (and thus pose food spoilage problems)
    Thermoduric (e.g. organisms which form endospores under high heat conditions)
  59. What is a significant factor for determining optimal environmental temperature?
    The optimal temperature for the function of its enzymes
  60. These organisms are tolerant of acidity (unlike the average bacteria which lives b/w 6.5 and 7.5 pH)
  61. Bacteria that ferment cheese and generate acids as a byproduct are an example of what type of organism
  62. These organisms tolerate higher osmotic pressures, especially:  higher salt concentrations (greater than 2%, as high as 30% in the Dead Sea)
  63. This occurs when water moves out of a cell due to high external concentration of solutes (high osmolarity)
  64. Isotonic Solution
    Solution in which the solute level in the external environment matches the solute level in the internal (cellular) environment
  65. Hypertonic Solution
    Solution in which the external environment contains a larger concentration of solutes and thus induces shriveling of cells and ultimately plasmolysis
  66. Hypotonic Solution
    Solution in which the external environment contains a lower concentration of solutes and thus induces swelling (and ultimately bursting) of cells
  67. This is a main component of most any cell composing ~14%
  68. Bacterial sources of Nitrogen include...
    • Decomposing Amino Acids (which may be obtained directly from a growth medium)
    • Ammonium Ions (NH4+)
    • Nitrate Ions (NO3-)
    • Nitrogen Gas (N2)
  69. Bacterial sources of Sulfur include...
    • Amino acids
    • Sulfate (SO4)
    • Hyrogen Sulfide (H2S)
  70. Some bacteria REQUIRE certain amino acids. Others require certain vitamins
  71. About 100 years ago he developed the enrichment culture (somewhat of a precursor to streaking for isolation)
    Martinius Wilheim Beijerink
  72. This is a broth which is suitable to a single type of bacteria and will thus promote that bacteria's growth to the exclusion of other bacteria
    Enrichment culture
  73. Obtaining a "PURE" bacterial culture via the use of repeated transfer to fresh enrichment cultures is commonly used for what 2 types of samples?
    • Soil
    • Fecal
  74. Primary means of bacterial growth (reproduction)
    Binary Fission
  75. In this form of reproduction/growth, the bacterium elongate, reproduce their DNA, then divide in two
    Binary Fission
  76. In this form of reproduction/growth the bacteria develop an outgrowth into which a second nucleoid (containing a duplicate DNA) is moved.  This outgrowth eventually separates from the parent cell and grows from there to adult size
    Budding (e.g. saccharomyces cerevisiae)
  77. This process of reproduction/growth is used by a few filamentous bacteria
    Spore creation:  a bit of filament branches off and moves into the end of a branch which forms a spore then breaks off and germinates (scatters and grows into new bacteria)
  78. This process of reproduction is used by some filamentous bacteria such as cyanobacteria
    Fragmentation--a piece simple separates and moves elsewhere to grow
  79. Generation Time
    Means of expressing bacterial growth:  the time it takes for a cell to divide
  80. Generation Time of E. Coli
    20 minutes under ideal conditions (i.e. 20 generations or 1 million cells in 7 hours)
Card Set
Microbiology Exam 1
Lectures 1-6