Intro to Micro

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Intro to Micro
2012-02-28 08:15:44

Intro to Microbiology
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  1. What are 3 roles of the clinical microbiologist?
    • Recover organisms from patient specimens
    • Isolate and identify organisms
    • Interpret antimicrobial susceptibilities
  2. Give examples of structural arrangements for prokaryotic cells.
    • single or individual
    • pairs - diplo
    • chains - strep
    • clusters - staphylo
    • tetrads - group of 4 cells
    • Sarcinae - group of 8 cells
  3. Determine classification:
    No Nucleus
    No Organelles
    single molecule of DNA
    peptidoglycan in cell wall
    binary fission
    Prokaryotic (Bacteria)
  4. Determine classification:
    True Nucleus
    Organelles (many)
    DNA discrete packages (chromosomes)
    no peptidoglycan in cell wall
  5. What are the four main functions of the bacteria cell wall?
    • Maintains cell shape
    • Protects cell from adverse conditions
    • Protects cell from osmotic lysis
    • Provides anchorage for flagella
  6. Give three reasons why the bacterial cell wall is clinicaly important.
    • It's ability to cause disease
    • Site of action of some antibiotics
    • Chemical composition helps in bacterial identification
  7. What are three things that make up the bacterial cell wall?
    • Peptidoglycan
    • Disaccharides
    • Polypeptides
  8. What key items make up the Gram Positive cell wall?
    • Many layers of peptidoglycan (thick and rigid) 20 layers
    • Teichoic acid
  9. What is are the functions of teichoic acid?
    • Bind and regulate the movement of positive ions
    • prevents cell lysis during growth
  10. What are the two items that a gram negative cell wall is composed of?
    • Outer membrane
    • Thin layer of peptidoglycan in periplasm
  11. What is the gram negative cell wall outermembrane composed of?
    • Lipoproteins
    • Lipopolysaccharide
    • Phospholipids
    • Porin proteins
  12. What are two types of lipopolysaccharides that make up the gram negative cell wall?
    • O Polysaccharides
    • Lipid A
  13. What are 4 features of a glycocalyx?
    • Viscous gelatinous consistence (sticky)
    • Made of polsaccharide or polypeptide
    • Made inside and excreted outside the CW
  14. Name the two types of glycocalyx.
    • Capsule
    • Slime Layer
  15. What are 4 functions of the glycocalyx?
    • Protects organism from phagocytosis
    • allows adherence to surfaces
    • may be used as nutrient by some bacteria
    • protects against dehydration
  16. What is flagella?
    Long filamentous appendages providing motility on their own.
  17. Name the four types of flagellar arrangements.
    • Monotrichous - single, polar flagellum
    • Amphitrichous - tuft at each end
    • Lophotrichous - 2 or more flagella at one pole
    • Peritrichous - around entire cell
  18. What is the purpose of axial filaments, and how do they work?
    • Bundles of fibrin arising at the ends of the cell beneath the outer sheat
    • Wrap around the whole cell
    • rotation of outer sheath propels the cell in spiral motion
  19. What are cells that have axial filaments called?
  20. What is fimbria composed of and what is it's overall function?
    • Fimbriae is composed of hairlike appendages made of pilin(protein).
    • Fimbriae's overall function is attachment (adherence to surfaces)
  21. What is the function of pilus?
    Used to join bacterial cells to transfer DNA
  22. What are two features of O polysaccharide?
    • Is antigenic (A substance that when introduced into the body stimulates the production of an antibody)
    • Basis for serotyping
  23. What are two features of Lipid A?
    Releases endotoxins that cause fever and shock.
  24. What are traits of an acid fast cell wall?
    • Gram positive cell wall
    • Waxy layer which is more resistant to antibiotics and is composed of glycolipids and fatty acids
  25. Identify the cell structure:
    Encloses cytoplasm
    Made up of phospholipid bilayer with proteins
    Shape mediator
    Plasma Membrane
  26. What are the two main functions of the plasma membrane?
    • Selective barrier
    • Metabolic functions (enzymes)
    • *nutrient breakdown
    • *synthesis of ATP
    • *photosynthesis (in plant cell)
  27. What are 3 agents that affect the plasma membrane?
    • antibiotics
    • alcohol
    • dissinfectants
  28. What is the cytoplasm and what is it composed of?
    • Substance inside the plasma membrane
    • Houses the organelles
    • Composed of 80% water with proteins, CHO, lipids etc.
  29. What is number 2 pointing at:
    Extrachromosomal DNA
    Replicated independently
    No need for survival
    Provide advantages such as resistance to antibiotics and toxins
  30. Name this organelle:
    Site of protein synthesis
    Composed of 2 subunits: 50s & 30s = 70s
    Each subunit consists of rRNA and proteins
    Target for certain antibiotics
    Prokaryotic Ribosomes
  31. When the evironmental conditions become adverse some bacteria create these.
  32. What is the function of cilia?
    Moving substances along the surface of the cell and locomotion.
  33. What are the 3 functions of the cytoplasmic membrance? (eukaryotic)
    • Provides structure
    • Passive and active transport processes for the movement of substances
    • Endocytosis to include phagocytosis and pincocytosis
  34. What is the nucleus composed of?
    • Nuclear envelope
    • Nuclear pores
    • Necleoli
    • Majority of DNA
  35. What are the different types of bacterial stains?
    • Gram stain
    • Acid fast
    • India Ink
    • Calcofluor White
    • Lactophenal Cotton blue
  36. What are the four components that make up the gram stain?
    • Crystal violet
    • iodine
    • alcohol decolorizer
    • safranin
  37. What are the 3 major needs for microbial growth?
    • carbon
    • nitrogen
    • ATP
  38. What are the two main catergories in microbial growth?
    • physical - temperature, pH
    • chemical - H2O, C & N
  39. What are the 3 primary groups based on temperature range?
    • Psychophiles - cold loving - 10 – 20◦
    • Mesophiles - moderate temperature loving - 20 – 40◦
    • Thermophiles - heat loving - 50 – 60◦
  40. Most bacteria grow best in what pH range?
    6.5 - 7.5
  41. What pH range do yeasts and molds prefer?
    5 - 6
  42. The force with which a solvent moves from an area of lower solute concentration to a solution of higher solute concentration
    osmotic pressure
  43. Shrinkage of the cell in hypertonic solutions.
  44. Require high salt concentration for growth
    Extreme halophiles
  45. Do not require high salt concentration but can tolerate up to 2%
    Falcultative halophiles
  46. What is needed for all organic compounds in cell
  47. What are other chemical requirements needed for microbial growth aside from carbon?
    Nitrogen, sulfure, phosphorus, oxygen and trace elements of iron, copper etc.
  48. How is oxygen handled by cells?
    • combining O2 with H atoms that were removed from organic compounds to form H2O
    • Process yeilds energy
    • Aerobic respiration
  49. Oxygen required for growth
    obligate aerobes
  50. Can grow with or without oxygen
    falcultative anaerobes
  51. Unable to use molecular oxygen
    obligate anaerobes
  52. Tolerate to oxygen but do not use it for growth
    aerotolerant anaerobes
  53. Decreased oxygen concentration
  54. What are 4 examples of essential compounds the organism is not able to synthesize on it's own?
    • Amino Acids
    • Purines
    • Pyrimidines
    • Vitamins
  55. What are 3 bacterial culture requirements?
    • sterile media
    • proper temperature
    • proper culture media to support growth of desired microorganisms
  56. What are 4 types of media?
    • Nutritive - basic components to support most bacterial growth
    • Enriched - extra nutrients added that encourages growth
    • Selective - inhibits growth of unwanted organisms through, salts, dyes, other chemicals
    • Differential - contain compounds that allow differentiation based on metabolic differences
  57. What are four types of bacterial division?
    • Binary fission - most
    • Budding
    • Aerial Spore
    • Fragmentation
  58. Time for a cell to divide and it's population to double
    Generation time
  59. Little or no cell division
    Lag phase
  60. Exponential growth
    Log phase
  61. Population stabilizes
    growth rate = death rate
    Stationary phase
  62. Death is greater than growth
    Death phase or Log decline
  63. What are 4 methods for measuring microbial growth?
    • Plate counts
    • density measurment (turbidity)
    • direct microscopic count
  64. What is a bacterial colony?
    • Population of cells arising from a single bacterium
    • Visible with the naked eye on culture medium
  65. Sum of all chemical reactions that occur in an organism.
    Either require or release enegery
  66. What are the two classes of chemical reactions?
    • Catabolism
    • Anabolism
  67. Identify the chemical reaction class:
    Release (E)
    breakdown complex organic compounds
    usually hydrolytic reactions
    exergonic reactions
  68. Identify the chemical reaction class:
    Reactions that require (E) to create new bonds
    Synthesis of complex organic compounds
    involve dehydration rxns
    generate materials for cell growth
  69. The following steps are included in what process:
    Bacteriophage attaches to bacterial cell wall
    Injects DNA into cell
    Synthesizes new phage DNA and protein coats
    Donor cell lysed and phage released
    Phage infects new bacterial cell
    Donor bacterial DNA recombines with reipient
  70. Organisms that colonize a host with causing disease
    Normal Flora
  71. Organism that does not normally cause disease but can become pathogenic under certain conditions
  72. A disease causing organism
  73. Manner in which a disease develops
  74. Ability of organism to cause disease
  75. Degree of pathogenicity
  76. disease constantly present in a certain population
  77. Disease aquired by many people in a given area in a short time
  78. Incidence of a specific disease
  79. # of deaths associated with a specific disease
  80. Organismm that lives at the expense of the host
  81. Organism that benefits from the host
  82. Organism that has a neutral affect on the host
  83. host infected with a pathogenic organism with manifesting disease
  84. infection aquired during hospitilization.
    nosocomial infection
  85. Aquired as an infant
    competes with pathogens for nutrient space
    sythesize nutrients in intestinal tract
    contributes to overall health of the host
    Normal Flora
  86. Self feeders
    use CO2
    also called lithotrophs
  87. Feed on others
    Require an organic C source
    also called organotrophs
  88. Nutrients from dead organic matter.
  89. Gene has gone through translation and produced a functional protein
    Expression (expressed gene)