micro bio

Card Set Information

micro bio
2013-10-17 08:51:23
2nd exam

study guide
Show Answers:

  1. endospore
    • differentiated forms of bacteria that can withstand extremes
    • highly resistant to being destroyed
    • metabolically inactive
    • can germinate in favorable condition
  2. endospore cortex is make of:
    peptidoglycan and has protein layers outside
  3. endospore cortex function
    helps draw the water out which adds to the toughness
  4. calcium dipicolinic acid
    (salt) binds to water, reduces availability for being a solvent
  5. SASP
    • Small Acid Soluble Protein;
    • binds to DNA and converts it to a more compact and UV resistant form (A-form)
  6. spore coat
    made of protein and provides chemical resistance
  7. binary fission steps
    • 1. DNA replicates (rod shaped elongates)
    • 2. Proteins bind to DNA and segregate it to the poles 
    • 3. Formation of the division septum
    • 4. Cell separates into 2 cell components and cell wall follows and fills in.
  8. genuses with endospores
    • bacillus + clostridium 
    • soil + dwelling
  9. endospores form during
    periods of low nutrients or other poor growth conditions
  10. endospores allow for:
    survival and dispersion
  11. endospores can ? for possibly thousounds of years
    remain dominant
  12. exosporiums purpose
  13. bacillius and clostridium are ? shaped and gram ?
    rod shape and gram +
  14. core of spore had little H2O which helps with:
    heat resistance, less solvent to carry toxic chemical
  15. ? microscopy is used to view cortex
  16. septum
    cell membrane envaginates cell wall synthesized
  17. bacterial cells do not undergo
  18. in sporlulation, the septum is formed ?
  19. in sporulation, each compartment had its own ?
  20. sporulation steps:
    • 1. septum formed
    • 2. mother cell engulfs forespore
    • 3. maturation begins
    • 4. cortex forms
    • 5. protein coat is built
    • 6. loss of water
    • 7. mother cell lyses and spore is resealed.
  21. polar flagella
    on end
  22. peritrichous flagella
  23. bipolar flagella
    both ends
  24. Iophotrichous flagella
    multiple ends
  25. reversible flagella
    can go back and forth
  26. undirectional flagella
    cell can stop, reorient and then continue allowing it to go in any direction
  27. flagella are made of
    protein subunits
  28. flagella use a ??? to spin
    proton motive force
  29. pili cause a ? movement
  30. flagella have a ? shape which helps them move through liquid medium
  31. in flagella growth, the newest material is located where
    at the end of the flagella
  32. to move forward, peritrichous flagella
    are bundled together
  33. to tumble, peritrichous flagella
    are pushed apart
  34. gliding motility
    • movement across a solid surface
    • no flagella
    • uses a protein force
  35. chemotaxis
    • attraction or repulsion due to a chemical 
    • can cause medium before and after run, adjusting size of run (according to distance from attractant)
  36. no attractant causes
    random movement
  37. photoaxis
    attractant = light
  38. aerotaxis
    relative to an oxygen concentration
  39. osmotaxis
    relative to density
  40. scotophobotaxis
    energy cells have in a certain light do not move in the dark
  41. macro-nutrients: carbon
    • carbs, proteins, lipids, nucleic acids
    • 50% of dry weight of a cell
  42. macro-nutrients: nitrogen
    • protein and nucleic acid
    • informational molecules 
    • needed for production of amino acids (proteins) nitrogenous bases (nucleic acids) and peptidoglycan (polysaccharides)
  43. macro-nutrients: phosphorus
    • nucleic acids, phospholipids
    • energy conservation molecules
  44. macro-nutrients: sulfer
    some amino acids and vitamins
  45. macro-nutrients: potassium
    enzyme synthesis
  46. macro-nutrients: magnesium
    • stabilizes negatively charged molecules 
    • (protein, membrane and nucleic acid)
    • for some enzyme activities
  47. macro-nutrients: calcium and sodium
    may be needed for cell wall stabilization and sporulation
  48. micronutrients / trace elements
    neeeded in small amounts
  49. iron
    • scarce
    • needed by most microbes (some found a way to get around needing it)
  50. siderophores
    binds to iron in order to bring it into microbe
  51. hydroxamates
    • combines with ferric (oxidized) iron and brings it into the cell
    • reduces it to ferrous iron
  52. enterobactin
    • can bind ferric iron outside of the cell and bring it into the microbe
    • found in enteric bacteria (gut)
  53. aquachelin
    • not free floating 
    • bound to membrane via hydrophobic tail 
    • brings in the ferric form and reduces it
    • found in marine organisms
  54. iron most commonly found as
    • ferric
    • insoluble (not capable of being dissolved)
  55. irons useful forms
    • ferrous 
    • soluble
  56. catabolism
    • energy yielding reaction (break down energy source) 
    • 1. phototrophic reaction (light)
    • 2. chemotrophic reactions (chemical) 
    • 3. oxidation of complex substrates
  57. anabolism
    • energy requiring reaction (require energy to work in a cell)
    • building the structures required for growth
    • reduction steps
  58. defined media
    exact chemical composition and amounts KNOWN 
  59. complex media
    • unsure of the relative amounts of nutrients 
    • easy to make
    • cheaper
    • EX: blood agar
  60. selective media
    • prevent things you dont want
    • encourages things you do want
  61. nonselective media
    rich, EVERYTHING grows
  62. differential media
    visible difference between organisms
  63. solid media
    organisms on surface can isolate individual colonies
  64. liquid media
    • can change concentration
    • centrifuge
  65. trace element solution
    take trace amounts of each and makes a solution needed for growth
  66. minimal medium
    simplest defined minimal amount you can give to an organism and still grow
  67. MacConkey agar
    • contains bile salt and crystal violet to inhibit other bacteria
    • contains lactose and pH indicator to differentiate lactose fermenters
  68. Eosin-Methylene Blue agar
    • contains Eosin Y (inhibits gram +) and methylene blue as well as lactose 
    • E.coli forms a metallic sheen (gloss) due to high lactose fermentation
  69. free energy
    energy released from a reaction that can be used to do work
  70. exergonic
    • delta G0' (-)
    • favorable reaction
    • releases energy
    • catabolism
  71. Endergonic
    • Delta G0' (+) 
    • unfavorable reaction
    • requires energy
  72. delta G0'
    standard conditions
  73. delta G0
    actual/natural conditions
  74. enzymes
    • proteins that lower activation energy for a reaction
    • catalysts: speed up reaction
    • specific (3D polypeptide structure)
    • not consumed in reaction
    • does NOT change bioenergetics (free E that can result) of the reaction
  75. substrates bring to the
    active sites
  76. prostheitc group
    • bound to enzyme
    • non-peptide 
    • tightly bound as part of the enzyme complex
    • covalently linked to peptide
    • EX: heme group
  77. coenzyme
    • loosely bound to emzyme
    • assist in reaction
    • non-peptide
    • may associate with several different enzymes 
    • most derived from vitamins 
    • EX: NAD+/NADH
  78. redox reactions
    one molecule is reduced, one is oxidized
  79. oxidizing agent
    • gets reduced
    • gains electrons (H)
    • acceptor
  80. reducing agent
    • gets oxidized
    • loses electron (H)
    • donor
  81. top of chart
    • want to be oxidized
    • good DONORS
  82. lower on chart
    better electron acceptor
  83. in a cell, the transfer of electrons from donor to acceptor typically involves one or more ?
    electron carries
  84. "from"
    electron donor
  85. "to"
    electron acceptor
  86. ATP
    main carrier/ currency of energy
  87. ATP has energy stored in what
    anhydride bonds
  88. examples used for long term energy storage
    • 1. glycogen (polyglucose-polysaccharides)
    • 2. poly-B-hydroxybutyrate (lipid)
    • 3. sulfer polymers-inorganic molecues used by sulfer
    • 4. chemolithotrophs
  89. the energy released in redox reactions is conserved in the formation of certain compounds that contain what
    energy rich phosphate or sulfer bonds
  90. formation of polymers
    longterm storage of energy
  91. polymers can be consumed to yield what
  92. substrate level phosphorylation
    • 1.ATP generate at specific reaction steps
    • 2.fermentation mechanism
    • 3.can give up phosphate to change ADP to ATP (phosphate transfer)
  93. oxidative phosphorylation
    • 1.ATP generated via proton motive force
    • 2.respiratory mechanism 
    • 3.required cytoplasmic membrane participation (membrane divides protons and electrons)
    • 4. generates proton gradient
  94. photophosphorylation
    used in phototrophs (similar to oxidative phosphorylation)
  95. glycolysis
    • 1. nets 2 ATP
    • 2. ATP forms through substrate level phosphorylation
    • 3. not the most efficient (carbon is not completely oxidized)
  96. electron transport carrier: NADH 
    • membrane bound
    • binds NADH
    • transfer 2e- and 2H flavoproteins
  97. electron transport carrer: Flavoproteins
    • derived from riboflavin
    • accepts 2e- and 2H+ from NADH dehydrogenase
    • donates 2e- to next carrier
  98. electron transport carrier: iron-sulfer proteins
    • non-heme iron proteins
    • only carries electrons
    • contains Fe-S clusters coordinated by cysteines in protein 
    • reduction potentials vary from protein to protein
  99. electron transport carrier: cytochromes
    • heme prosthetic groups/iron center
    • 1e- in 
    • 1e- out (single electron transfer)
    • several classes with varying reduction potentials
  100. electron transport carrier: quinones
    • hydrophobic (found in membrane) NON-PROTEIN 
    • accepts 2e- and 2H+ from prvious carrier
    • donates 2e- to next carrier
  101. oxidative phosphorylation
    • uses energy from electrons to pump hydrogen ions out of the cell, creating a gradient across the membrane 
    • protons flow from high to low concentrations 
    • concentration through ATP aynthase, phosphorulating 
    • ADP to ATP
  102. ATP synthase/proton motive force
    protons that rush through ATPase cause a rotary force of the complex to generate ATP
  103. aerobic respiration
    use of oxygen as the terminal electron acceptor
  104. aerobic respiration as electron transfer
    from organic substrate to terminal electron acceptor with concomitant extrusion of protons across membrane
  105. aerobic respiration as pathway of oxidation
    of organic substrate to form CO2
  106. electron chain transport
    • discrete transfer steps help conserve energy throughout oxidation
    • electron transport allow for separation of protons from electrons
  107. transfer of  charges the membrane like a battery
    PROTONS to the outside (accumulation of OH- inside)
  108. potential energy created in an electron transport chain is used to ?
    do work in the cell
  109. inhibitors
    • block electron transport, preventing the establishment of a proton gradient 
    • EX: carbon monoxide and cyanide 
  110. uncouplers
    • allow protons to pass across the membrane (by making them leaky) bypassing the use of ATPase
    • EX: dinitrophenol
  111. the citric acid cycle
    • uses products of glycolysis (pyruvate) to obtain electron carriers NADH and FADH
    • VERY efficient
  112. citric acids cycle products
    • 6 CO2
    • 3 NADH
    • 1 FADH2
    • 1 NADPH
    • 1 GTP
  113. NADH & FADH2
    carry 2e- into electron transport chain
  114. in the citric acid cycle, glucose is what?
    completely oxidized
  115. more efficient: respiration or citric acid cycle
  116. anerobic respiration
    using something other than oxygen as terminal electron acceptor
  117. chemolithotriphy
    electrons start on reduced inorganic compounds (NOT carbon)
  118. phototrophy
    • light excites the electrons
    • photosynthesis (aerobic/anerobic)
  119. photoautotrophy
    carbon from CO2
  120. photoherterotrophy
    • carbon from organic compounds 
    • intermediate carbon compound not oxidized to get energy
  121. catabolic alternatives
    • anerobic respiration 
    • chemolithotrophy 
    • phototrophy