Micro I Exam 2

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Micro I Exam 2
2013-01-15 18:28:49
Physiology Bacteria

Micro I Exam 2 Physiology of Bacteria
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  1. increase in cell number
    • microbial growth
    • reproduction
  2. immediate consequence of cell division
    increase in cell number
  3. cell division for most prokaryotic organisms
    binary fission
  4. simple transverse division
    binary fission
  5. asexual form of reproduction
    binary fission
  6. binary fission process
    • cell increases in size
    • DNA replicates
    • mesosomes pull apart the copies of DNA
    • a new cell wall is formed
    • cell membrane is formed
    • two new daughter cells
  7. doubling time
    bacterial generational time
  8. the time it takes a cell to do one binary fission
       starting from having just divided
       ending at having just completed the next
    doubling time
  9. vary depending on organism and environment
    generation times
  10. range from 20 minutes for a fast growing bacterium under ideal conditions, to hours and days for less than ideal conditions of for slowly growing bacteria
    generation times
  11. no bacterial cell is exactly the same as another
    variations in genetic makeup
  12. changes in genetic make up of a cell can be caused by
    • external influences
    • internal influences
  13. external influences on variations in genetic makeup
    • a. kind of culture medium
    • b. temperature of growth
    • c. length of time grown artificially
    • d. exposure to chemicals or radiant energy
  14. internal influences on variations in genetic makeup
    • a. mutation
    • b. intermicrobial transfer
  15. alteration in the DNA sequence causing a change in form

    (usually lethal)
  16. intermicrobial transfer
    • 1. transformation
    • 2. conjugation
    • 3. transduction
  17. - a donor cell dies and releases DNA into the medium
  18. - this DNA breaks into many small fragments
  19. - a recipient cell will pick up a fragment of this DNA and incorporate the genetic information into its own DNA
  20. a sexual form of reproduction
  21. 2 cells unite by a sex pilus
  22. DNA slowly transfers from one cell to the other
  23. as this process is occurring, the pilus breaks allowing only a portion of the DNA to be transferred
  24. this fragment of DNA then recombines with the DNA of the recipient cell causing chanages
  25. an indirect transfer of DNA by a virus
  26. a virus carries a fragment of DNA from the cell where it was formed and enters a new cell
  27. the virus takes over the controls of this cell and the genetic material is incorporated into the DNA of the new cell
  28. as the cells continue to divide the mass of cells become visible to the human eye
    bacterial colony
  29. a visible mass of vegetative bacterial cells
    bacterial colony
  30. the environment must provide them with many specific substances and conditions
    for bacteria to grow and reproduce
  31. conditions affecting bacterial growth
    • 1. food requirements
    • 2. oxygen requirements
    • 3. moisture (water) requirements
    • 4. temperature requirements
    • 5. hydrogen ion concentration (pH)
    • 6. effects of light
    • 7. Osmotic pressure
    • 8. bacterial associations
  32. food requirements
    • a. autotrophic bacteria
    • b. heterotrophic bacteria
  33. organisms that require only inorganic substances for growth
    autotrophic bacteria
  34. they are self-sufficient and able to produce their own nutrients
    autotrophic bacteria
  35. they are free-living and do not associate with a living host or cause disease
    autotrophic bacteria
  36. heterotrophic bacteria
    • 1. strict or obligate saprophytes
    • 2. strice of obligate parasites
    • 3. facultative saprophytes
    • 4. facultative parasites
  37. organisms that require one or more organic compounds for growth
    heterotrophic bacteria
  38. all pathogenic organisms are
  39. they require dead organic matter for nutrition
    strict or obligate saprophytes
  40. they require living organic matter for nutrition
    strict or obligate parasites
  41. they must have a living host
    strict or obligate parasites
  42. prefer living organic matter but can survive minimally with dead organic matter
    facultative saprophytes
  43. prefer dead organic matter but can survive minimally with living organic matter
    facultative parasites
  44. to prefer the condition NOT named
  45. oxygen requirements
    • a. strict or obligate aerobes
    • b. strict or obligate anaerobes
    • c. microaerophilic organisms
    • d. facultative aerobes
    • e. facultative anaerobes
    • f. capnophilic organisms
  46. must have free atmospheric oxygen as found in the air in order to survive
    Strict or obligate aerobes
  47. they require the absence of free atmospheric oxygen
    strict or obligate anaerobes
  48. these acquire oxygen for metabolism by breaking down food sources that contain oxygen
    strict or obligate anaerobes
  49. require only small amounts of oxygen
    microaerophilic organisms
  50. they may not grow better but can survive in the presence of free atmospheric oxygen
    microaerophilic organisms
  51. they prefer the absence of of free atmospheric oxygen but can survive in its presence
    facultative aerobes
  52. prefer the presence of free atmospheric oxygen but can survive without it
    facultative anaerobes
  53. require an increased level of carbon dioxide
    capnophilic organisms
  54. as for any cell, the presence of water is a requirement for survival
    moisture (water) requirements
  55. water acts as the solvent to carry nutrients into & wastes out of the cell
    moisture (water) requirements
  56. provides for the hydrolysis of nutrients
    moisture (water) requirements
  57. water provides 75-80% of the total cell weight
    moisture (water) requirements
  58. the absence of water will lead to dehydration and death of the cell
    moisture (water) requirements
  59. all bacteria have a temperature range that is required for growth but it varies from one organism to another
    temperature requirements
  60. temperature requirements
    although the ranges may vary, all bacteria will have the following requirements
    • a. minimum temperature
    • b. maximal temperature
    • c. optimal temperature
    • d. classification of bacteria in relation to temperature range
  61. the lowest temperature at which a particular organism will grow
    minimum temperature
  62. the highest temperature at which a particular organism will grow
    maximum temperature
  63. the temperature at which an organism prefers to grow and will grow the fastest
    optimum temperature
  64. classification of bacteria in relation to temperature range
    • 1. psychrophiles or cryophiles
    • 2. mesophiles
    • 3. thermophiles
  65. prefer cold temperatures
       between 0o-15oC
    psychrophiles or cryophiles
  66. prefer midrange temperatures
       between 25o-45oC
  67. most human pathogens are found in this group
  68. prefer high or hot temperatures
       anything above 45oC
  69. these will not cause disease because human body temp is too low for them to survive
  70. bacteria grow at a wide range of pH values
    Hydrogen Ion Concentration (pH)
  71. human pathogens grow best in a neutral or slightly alkaline environment
      between 6-8 pH
    Hydrogen Ion Concentration (pH)
  72. making the pH of the body the perfect environment
    Hydrogen Ion Concentration (pH)
  73. exception to Hydrogen Ion Concentration (pH)
    Lactobacillus prefers a pH of 5 or less
    known as an acidophile
  74. exception to Hydrogen Ion Concentration (pH)
    Vibrio prefers a pH of 9 or above
    known as an alkaliphile
  75. all light is harmful to the growth of bacteria
    effects of light
  76. the most harmful is ultraviolet(UV) light
    effects of light
  77. as it passes through the cell it alters the structure of the DNA
    ultraviolet(UV) light
  78. causes mutations to occur that are lethal to the cell
    ultraviolet(UV) light altering the structure of the DNA
  79. causes changes in their size, volume, and viability
    osmosis that occurs in bacterial cells
  80. a cell that is present in a hypertonic environment
    will shrink in size
  81. there is a greater amount of solute outside the cell than inside
    hypertonic environment
  82. this draws water out of the cell causing the cell to shrink
    hypertonic environment
  83. the shrinkage of cells
  84. a cell that is present in a hypotonic environment
    will increase in size
  85. there is a greater amount of solute inside this cell than outside
    hypotonic environment
  86. this draws water into the cell causing swelling to the point of bursting
    hypotonic environment
  87. the swelling of cells to bursting
  88. a cell that is present in an isotonic environment
    will show no appreciable change
  89. there are equal amounts of solute inside & outside the cell
    isotonic environment
  90. moisture still moves in & out of the cell, but at an equal rate
    isotonic environment
  91. the fact that interrelationships exist between biological organisms requires that we examine how these relationships effect the growth and survival of bacteria
    bacterial associations
  92. bacterial associations
    there are several types of relationships to be considered
    • a. symbiosis or mutualism
    • b. synergism
    • c. commensalism
    • d. antagonism or antibiosis
    • e. parasitism
  93. the relationship in which two organisms grow well together and cannot survive without each other
    • symbiosis
    • mutualsim
  94. the relationship in which two organisms grow well together but can survive alone
  95. they do better together but the relationship is not required
  96. means "to eat at the same table"
  97. the relationship in which two organisms are growing together but there is a benefit to one organism while there is no effect to the other
  98. the second organism is neither benefitted nor harmed
  99. the relationship between two organisms in which one organism is harmed by the presence of the other
    • antagonism
    • antibiosis
  100. is often due to to the production of a substance by one bacteria that inhibits the growth of kills the other organism
    • antagonism
    • antibiosis
  101. the substance formed can be referred to as an antibiotic
    • antagonism
    • antibiosis
  102. the relationship between two organisms in which one organism acts as a host for the other
  103. the parasite gains nutrition, protection, & livelihood from the host
  104. usually at the expense of the host
  105. organic catalysts
  106. cause the physiological chemical reactions that occur in living cells to be started or to be carried to completion
  107. they are protein by nature
  108. the name always ends with -ase
  109. the substance upon which an enzyme will act
  110. the organic compounds present in the cell
  111. every organic compound has a specific type of enzyme that will react with it
  112. every enzyme is very specific as to what ____ it will react with
  113. carbohydrase reacts upon
  114. protease reacts upon
  115. lipase reacts upon
  116. nuclease reacts upon
    nucleic acids (RNA & DNA)