Microbiology EXAM 1

  1. what are the morphologies of bacterial cells
    • coccus (cocci)
    • bacillus (bacilli)
    • coccobacillus
    • vibrio
    • spirillium
    • pleomorphic
  2. what is the morphology of coccus
    sperical. perfect spheres
  3. what is the morphology of bacillus
    rod. perfect rods
  4. what is the morphology of coccobacillus
    short rods
  5. vibrio look like?
    short curved rods
  6. spirillium look like
    spiral rods
  7. pleomorphic shapes are
    variable. each cell looks different
  8. extracellular layer that holds bacterial cells together after cell division
  9. what is the good news of an organism that forms groups?
    it spreads more slowly
  10. what is the bad news of an organism that forms groups?
    it can hide from the Immune system longer
  11. allows bacteria to move from on place to another.

    alls cells to swim freely through an aquesous habitat.
  12. what are the three subtypes of flagella ?
    • - monotrichous
    • - lophotricphous
    • - amphitrichous
  13. what is monotrichous
    flagella with a single flagellum
  14. what is lophotricphous
    flagella with small bunches/tufts/groups of flagella emerging from the same site
  15. what is amphitrichous
    with flagella at both poles of the cell
  16. what is peritrchious flagella?
    arrangement of flagella are dispersed randomly over the surface of the cell
  17. flagella can detect and move to chemical signals this type of behavior is called
    ex: toward food and away from stimulus such as chemical toxins
  18. movement of a cell in the direction of a favorable chemicial stimuulus/ attractant (usually a nutrient)
    positive chemotaxis
  19. movement away from a repellent (potientially harmful) compound.
    negative chemotaxis
  20. in chemotaxis for flagella when it is swimming toward attractant the flagella will
    swim/run more and tumble less
  21. with flagella, if the bacteria is moving toward a repellent the flagella will
    tumble more and swim for shorter periods.
  22. swim toward/away from light
  23. swim toward/away from oxygen supply
  24. moving toward/away from magnetic field. coordinates movement in response to magnetic fields. ex: orient to earth's magnetic field
  25. small, bristlelike fibers emerging from the surface of many bacterial cells.
    - most contain protein.
    - tendency to stick to each other/ and surfaces.
  26. elongated, rigid tubular structure made of special protein.
    -only in gram-negative where they are utilized in "mating"
  27. mating process between cells.
    involves partial transfer of DNA of one cell to another.
  28. they may be responsible for the mutual clinging of cells that leads to biofilsm and other thick aggregates of cells on the surface of liquids and for the microbial colonization of inanimate solids such as rock and glass
  29. some pathogens can colonize and infect host tissues b/c of tight adhesion between their what?
    • fimbrae and epithelial cells
    • ex: gonoccus-agent of gonorrhea colonizes the genitourinary tract E. Coli colonizes the intestine by this means
  30. in the conjugation of pilus. a pilus from a donor cell unites with a recipent cell thereby providing...
    cytoplasmic connection for making the transfer
  31. inner most part of a bacterial cell
    cell wall
  32. forms thick layer over inner cell membrane. where cell walls gain their stability and strength from
  33. protects the cell from osmotic shock
    cell wall
  34. definition: a network of polysaccharide chains cross-linked by short peptides hat from the rigid part of bacterial cell walls
  35. a peptide inter-bridge between the Diaminopimelic Acid of one glycana chain and the D-Alanine of another. the composition of this inter-bridge varies between species
    Gram positive
  36. the tetrapeptides are joined directly
  37. examples: rubber cement, weak, soluble
  38. ex: rubber car tire, strong, tough, insoluble, lasts longer
  39. definition: think homogeneous sheath of peptidoglycan ranging from 20 to 80nm in thickness. also contains tightly bound acidic polysaccharides including: teichoic acid directly attached to peptidoglycan and lipoteichoic acid
    gram positive
  40. a polymer of ribitol or glycerol and phosphate embedded in peptidoglycan sheath. project outward from peptidoglycan layer. immunogenic
    Teichoic Acid
  41. attached to the lipids in the plasma membrane.
    project inward from peptidoglycan layer to cytoplasmic membrane- anchor.
    liboteichoic acid
  42. composed of an outer membrane and thinner shell of peptidoglycan. contains specialized types of LPS and lipoproteins.
    no peptide inter-bridge
  43. composed of lipid molecules bound to polysaccharides. the lipids form the matrix of the top laye of the OM and the polysaccharides strand project from the lipid surface.
    lipopolysaccharides LPS
  44. resistant to certain antibiotics
  45. inserted in the upper layer of the outer membrane. they have some regulatory control over molecules entering and leaving the cell.
  46. many qualities of the selective permeability of gram-negative bacteria to bile, disinfectants, and drugs are due to the
  47. just underneath the outer membrane.
    above and below peptidoglycan
    important reaction site for a large and varied pool of substances that enter and leave the cell.
    houses secreted degradative enzymes (pathology)
  48. disrupts cross-linking between glycan molecules (makes the pepto layer weak)
    more effective against gram+ b/c its excluded by prions in gram-
  49. largerly composed of mycolic acid making them appear waxy and more resistant to chemicas, dehydration, antibiotics (pathology)
  50. bacteria without a cell wall
    containssterols that make it resistant to lysis
    found in may habitats such as plants, soils and animals
  51. form or shape. tendency for cells of same species to vary in some extent in shape in size.
    mycoplasmas are this
  52. contain peptidoglycan and stain gram-positive, but the bulk of their cell wall is composed of unique types of lipids.
    ex: TB
  53. underneath the cell wall
    regulates transport into/out of the cell
    flexible sheet molded completely around the cytoplasm
    lipid bilayer with proteins emedded to varying degrees
    • cell membrane
    • 50% phospholipid
    • 50% integral membrane proteis
  54. polar head oriented toward the outside
    nonpolar head towad the center of the membrane
    embedded at numerous sites in this bilayer of various-size globular proteins
  55. freely permeable to water, dissolves gases, and small hydrophobic molecules by simple diffusion
    phospolipid bilayer
  56. too big to go through cells
    ex: glucose and amino acids
    hydophlic molecules
  57. how do bacteria acquire most of their raw materials?
    transport proteins
  58. what are the types of transport proteins?
    • symporters
    • antiporters
    • uniporters
  59. transport of two substances in the same direction
    ex: sugars
  60. transport of 2 substances in opposite directions
    ex: anitbiotics
  61. transports one substance in one direction (either in or out)
    ex: cations, potassium, calcium
  62. clever (esp. for bacteria)
    the substance is chemically altered during transport (phosphotranserase system)
    ex: glucose and other sugars
    the cell can soak up all the glucose by converting into glucose-phosphate
    group translocation
  63. how do bacteria sense and respond to their environment?
  64. transduce chemical signals from outside the cell to inside the cell
  65. a single, circular, supercoiled, double stranded DNA molecule.
    replicates only when the cell divides
    bacterial chromosome
  66. what are the types of bacterial chromosome
    • single
    • circular
    • dsDNA
  67. where one gene goes so do all the other (little variation)
    single bacterial chromosome
  68. easier to replicate than linear (humans have linear)
    circular bacterial chromosome
  69. like, ours and replicates like ours
    dsDNA bacterial chromosomes
  70. inside the bacterial cell
    the molecular machine that assembles amino acids into proteins
    comprised of 54 proteins and 3 RNAs
    target of many antibiotics
  71. withstands hostile conditions and faciliate survival.
    dormant bodies produced by bacteria Bacillus, and Clostridium.
    two-phase life cycle taht shifts between a vegative cell and an endospore
    exists in an inert, resting condition that is capable of high resistance and very long-term survival.
  72. the time required for a complete fission of cycle. from parent cell to 2 new cells is called
    generation or doubling time
  73. the period between an individuals's birth and the time of producing offspring. in bacteria each new fission cycle increases the population by a factor of 2, or doubles it
  74. a measure of the growth rate of an organism
    compared with the growth rates of most other living things, bacteria are notoriously rapid.
    average for bacteria is 30-60
    generation time
  75. Nt
    • the number of bacteria at a certain time
    • (what you have to try and calculate)
  76. N0
    the number of bacteria at the beginning
  77. n
    the number of times the bacteria divide
  78. how do you get n?
    • 1st in the generation time divide 60 min by those mins. for ex: if generation time was 20. divide 60 by 20 = 3
    • 2nd: times the answer for generation time by the elasped time to get n.
    • to solve for nt:
    • replace the value for n into the equation :)
  79. what do you get when nutrients are limited?
    • growth curve
    • it takes a little while for them to get inot your blood stream.
  80. what are the stages of growth curve?
    • lap phase
    • log phase
    • stationary phase
    • death phase
  81. period of adjustment
    no increase in cell number
    cells dont divide
    flat period on the graph when the population appears not to be growing or is growing at less than the exponential rate
    lag phase
  82. cell number doubles every generation
    (caused by unlimited nutrients)
    log phase
  83. no net incrase/decrease in cell number
    (cell division = cell dealths)
    (caused by depleted nutrients/build-up of toxic by products)
    stationary phase
  84. net decreased in cell number
    caused by prolonged stationary phase
    death phase
  85. what are major factors that control bacterial cell growth?
    • temperature
    • oxygen availability
    • energy/carbon source
    • ph
    • what avialability/concentration of water
  86. what is the temperatuure requirement for psychrophiles (many pseudomonas) ?
    below room temperature
  87. what are the temperature requirements for mesophiles (e. coli and all human pathogens) ?
    about room temperature
  88. what are the temperature requirements for thermophiles ( lactobacillus delbruekii- yogurt)?
    above room temperature
  89. what are the temperature requirements for hyperthermophiles (pyrolobus fumarimii -ocean vents)?
    extreme heats
  90. require the level of oxygen normally present in air
    obligate aerobes
  91. require the absence of oxygen
    obligate anaerobes
  92. can grow in the presence OR absence of oxygen but grow faster with oxygen
    facultative anaerobes
  93. require reduced levels of oxygen
  94. grow equally well in the presence as in the absence of oxygen.
    (they dont use oxygen at all so doesnt matter)
  95. types of energy sources
    • phototroph
    • chemotroph
    • lithotrophs
  96. derives its energy from the sun (plants)
  97. derives its energy from organic compounds (us, glucose, fatty acids)
  98. derives its energy from inorganic sources (rocks)
  99. what are the carbon sources
    • autotrophs
    • heterotrophs
  100. derives carbon from CO2
  101. derives carbon from organic compounds (sugars/amino acids/fatty acids)
  102. what are the combinations of carbon sources
    • photoautotrophs
    • chemoheterotrophs
    • photoheterotrophs
  103. derives energy from the sun AND carbon from CO2
  104. derives its eergy from organic compounds AND its carbon from organic compounds
  105. derives its energy from the sun AND its carbon from organic compounds
  106. ph sources are
    • neutrophile
    • acidophiles
    • basophiles
  107. grow best from pH 5 to pH 8 (most bacteria)
  108. grow best pH 5 (heliobacter pylori)
  109. grow best above pH 8 (Bacillius alcalophiles) few but not many
  110. what is a water availability source?
  111. tolerant to relatively high (10%) salt concentrations (staphylococcus some Archae)
  112. what are factors to consider in control?
    • 1. type of organism
    • 2. number of organisms present
    • 3. environmental conditions
  113. list the types of organisms we learned, from hardest to control to easiest.
    • Hardest
    • 1. prions
    • 2. endospores
    • 3. mycobacteria
    • 4. pseudomonas
    • 5. non-enveloped viruses
    • 6. vegetative bacterial cells/ enveloped viruses
  114. explain the number or organisms present as a factor to consider in control
    • decimal reduction time Dvalue
    • D value = time nessary to kill 90%
  115. explain the environmental conditions to consider in control?
    pH, temp, salt, (smoke) water
  116. what is the D value graph
    • REMEMBER START AT 0 and the given amount of bacteria to start with , then go each interval that is given ex: if D =30 go every 30 minutes 1000 bacteria to start w/
    • 0 --1000
    • 30 min--- 100
    • 1hr---10
    • 1hr 30min---1
    • 2 hrs--- less than 1
    • DONT FORGET to go until you have less than 1!!!
  117. what are physical methods for reducing bacterial populations?
    • Heat:
    • -dry
    • -moist
  118. 200 degrees C for 1.5 hours to for sterile (wire loop)
    dry heat
  119. 121 degrees C for 15 mins for sterile
    moist heat
  120. dehydrate vegetative cells
    • alcohols
    • (chemical control of bacterial populations)
  121. denature proteins disrupt the 3 d structure
    • aldehydes
    • (chemical control of bacterial populations)
  122. mutagenic
    ehtylene oxide (chemical control of bacterial populations)
  123. oxidizing agents (chemically alter proteins)
    • halogens
    • (chemical control of bacterial populations)
  124. react with sulfhydral groups (Hg)
    • Metals
    • (chemical control of bacterial populations)
  125. ozone (chemical control of bacterial populations)
    oxidizing agent
  126. peroxides (chemical control of bacterial populations)
    oxidizing agent
  127. destroy cell membrane/proteins (chloraspetic)
    phenolics(chemical control of bacterial populations)
  128. quatemary ammonium compounds (quats)
    (chemical control of bacterial populations)
    dirupt membranes
  129. types of radiation and bacterial populations
    • gamma
    • ultraviolet
    • x-rays
  130. what do gamma rays do
    penetrating, ionizing radiation to free radicals (very reactive)
  131. what are ultraviolet rays
    non penetrating to thymine dimers (TT) mutagenic
  132. what do x-rays do
    penetrating, ionizing radiation to double strand breaks in DNA (mutagenic)
  133. prevent population from getting bigger
  134. kill bacteria and decrase the size of the population
  135. classified based on their chemical structure, mechanism of action, and biological source
    • antibiotics
    • why is this important? if one type of antibiotic is ineffective a mechanistically different antibiotic should be used
  136. Beta-lactams
    effective against?
    • effective against: gram-positive bacteria
    • mechanism: inhibtis cross linking of cell way peptidolycan
    • examples: penicillins and cephalosporins
  137. Semi-synthetic penicillin
    effective against
    • examples:ampicillin and amoxycillin
    • effective against: gram-positive and gram-neg
    • mechanism: inhibits cross linking of cell wall ( peptidoglycan)
  138. Clavulanic Acid
    effective against
    • examples:clavamox (is clavulanic acid plus amoxycillin)
    • effective against:beta lactam resistant gram-positive and gram-neg bacteria
    • mechanism:suicide inhibitor of beta-lactamases (clavulanic acid)
  139. Aminoglycosides
    mechaism: inhibits translation (ribosomes) rna and the protein. if it cant make protein then it dies.
  140. glycopeptides
    effective against
    • examples: Vancomycin
    • effective against: gram-positive bacteria, esp. staphylococcus aureus mrsa
    • mechanism: inhibits steps in murein (component of the cell wall) (peptidoglycan) biosysnthesis
  141. polyeptides
    effective against/spectrum?
    • example: polymyxin
    • effective against/spectrum: gram-neg bacteria
    • mechanism: damages cytoplasmic membranes
  142. Rifamycins
    effective against/spectrum?
    • example: rifampicin
    • spectrum:gram-pos and gram-neg bacteria, esp. mycobacterium tuberculosis
    • mechanism: inhibits transcription (RNA polymerase)
  143. polyenes
    spectrum/effective against?
    • example: amphotericin (strephtomyces nodosus), nystatin(strephomyces noursei)
    • spectrum: fungi (candida)
    • mechanism: inactivate membrances containing sterols
Card Set
Microbiology EXAM 1
microbiology exam 1 spring 2012