Microbiology Unit 2 - Cells

  1. Membrane
    • layer of lipids that separates them from the outside world
    • monolayer, bilayer, double membrane
  2. Nucleolus
    ribosome assembly site
  3. Intron
    • A non coding sequence in a split gene
    • Present in most eukaryotic cells
  4. Exon
    coding sequence in a split gene
  5. Nucleoid
    • location in a prokaryotic cell where the prokaryotic DNA is located
    • Eubacteria & Archae
  6. Nucleus
    • A defining characteristic of a Eukaryote
    • Location where the chromosomes are located
  7. Chromosomes
    Independently replicating pieces of DNA that are passed on to daughter cells that code for at least some essential genes
  8. Nuclear Envelope
    double membrane surrounding the nucleus
  9. Mesosomes
    • extensions of the membrane into the cell sometimes forming sacs
    • important for photosynthesis
  10. Magnetosomes
    • granules of ferromagnetic iron oxide localized close to the flagella
    • allow magneotatic bacteria to migrate down in pond water to anaerobic environment
  11. Gas Vacuoles
    Made of a protein wall that forms a gas-tight sac
  12. Vacuoles
    • Eukayotes
    • Used for storage of food, maintenance of cell shape, elimination of waste
  13. Lysosomes

    small membrane sacs allow the breakdown of components that have been taken in from outside the cell or defective components w/in the cell

    sacs of digestive enzymes w/ a low pH
  14. Cytoplasmic Membrane
    • Barrier that defines the border of the cell
    • Phospholipid bilayer
  15. Cell envelope
    cell wall/cell membrane
  16. Cytoplasm
    • cell pool
    • main location of a cells biochemical and biosynthetic activities
  17. semi-permeable membrane
    • permeable to water and small unchanged molecules
    • retains metabolites and ions in the cell
  18. passive diffusion
    • things move down the concentration gradient across the semi permeable membrane
    • Ex: water, oxygen, nitrogen, carbon dioxide
  19. facilitated diffusion
    • Use of a protein to make a hole in the membrane that will allow molecules to diffuse down the concentration gradient
    • Permeases
    • Ex: some amino acids, some sugars
  20. Active transport
    Use of protein and energey to move a compound against the concentration gradient across the membrane
  21. Group Translocation
    moves certain sugars down the concentration gradient while modifying the sugar in an energy dependant way
  22. cell wall
    responsible for cell shape and protection agains osmotic lysis
  23. osmosis
    movement of water across a concentration gradient
  24. lysis
    exploding or breaking open
  25. phosolipid bilayer
    • two layers of lipids
    • 50% protein, 50% lipid
    • fluid
    • allows lipids and proteins to move w/in the phospholipid bilayer
  26. Capsule
    Polymer of sugar residues that coat the bacterium or eykaryote
  27. Flagella
    Whip-like structures that allow for rapid movment of the cell
  28. Pili
    • long rods that stick out from the surface of the cell
    • adhesion
  29. cilia
    • only in Eukaryotes
    • propel the cell in a whip-like movement
  30. 9 + 2 array
    9 microtubules on the outside and 2 on the inside
  31. chemotaxis
    movement of an organism towards or away from a chemical
  32. phototaxis
    movement to or from light
  33. Aerotaxis
    movement to or from oxygen
  34. Random Walk
    movement in a desired direction
  35. cytoskeleton
    actin, microtubules, and intermediate filaments making up the shape of most Eukaryotes
  36. Mitochondria
    • power house of the cell
    • where respiration occurs in Eukaryotes
  37. Endoplasmic Reticulum
    • part of the nuclear envelope
    • location at which membrane proteins can be insterted into the eukaryotic membrane and proteins are secreted out
  38. chloroplasts
    site of photosynthesis in plant cells
  39. Golgi Bodies
    membrane sacs allow for localization of different sets of enzymes that allow spec modifications of the protein
  40. centriole
    • microtubule organization center of the cell
    • 9+0 array
  41. microcompartments
    protein sacs that form organelles in bacteria
  42. diplo
  43. staphylo
    grape like clusters
  44. strepto
  45. tetrads
    groups of four cells
  46. sarcina
    groups of eight cells
  47. simple stain
    • Stains with a net + charge
    • The cytoplasm of the cell is - charged so the dyes are attracted to the interior of the cell by electrical charge
  48. negative stain
    • negative charged
    • same charge as bacteria so not attracted to bacteria
    • useful for visualizing the bacteria
  49. differential stain
    allows you to visualize two populations or structures at the same time so you can distinguish them from each other
  50. mordant
    chemical that fixes a dye in or on cells by forming insoluable compound and promoting retention of the dye
  51. Destain
    process where subset of cells are destained - dye is washed out
  52. Gram stain
    • divides most Eubacteria into either + or -
    • important in clincial micro
  53. Gram +
    thick peptidoglycan wall
  54. Gram -
    thin peptidoglycan wall
  55. Acid Fast stain
    stain which shows the Mycobacterium and Norcardia
  56. Endospore stain
    • staining of very heat resistant spores
    • Malachite green, steam, water, saphranin
  57. Peptidoglycan
    • Similar structure in all Eubacteria
    • Archae have pseudo-pep. that has simiiar components but different structure
  58. Teichoic Acid
    long suger molecule that is sometimes membrane anchored (lipo-)
  59. Inner membrane
    • Gram - wall
    • Cytoplasmic membrane of the cell
  60. Periplasm
    • Gram - wall
    • Space between two membranes of the cel
    • 1. Peptidoglycan (about 1 layer thick)
    • 2. Peri-plasmic proteins
    • 3. Brauns lipoprotein -anchors outer membrane to the peptidoglycan
  61. Cell wall associated proteins
    • Gram + wall
    • allow the cell to interact with external environment
  62. Outer membrane
    • Only in Gram - bacteria
    • layer containing LPS and Porins
  63. Porins
    proteins that form larger pores in the outer membrane through which small macromolecules can pass
  64. LPS
    • lipopolysachharide
    • Lipid A - extrememly toxic to animals and can cause septic shock
  65. Core region
    species specific polysaccharides
  66. Mycolic Acid
    • single layer of lipids membrane
    • essential to get nutrients across the layer of lipids
  67. Arabinogalactan
    • type of sugar attached to peptidoglycan
    • very long and allow for the addition of many mycolic acid molecules
  68. Endospore
    • G+ bacteria specific
    • No metabolic activity
    • Most heat-resistance form of dormancy known
  69. Cortex
    area b/t two membranes that contains the peptidoglycan
  70. Coat (of endospore)
    dense layer of protein that protects the endospore from toxic chemicals
  71. Exosporium
    loose lipid-protein; unknown function
  72. Sporulation
    formation of endospores
  73. Exospores
    • External spores
    • Several species of Archae form them
  74. Germination of exospore
    Activiation, Germination, Outgrowth
  75. Cyst
    • Formed by some bacteria and some eukaryotes
    • Thick walled cells that form when nutrients are exhausted
    • Generally resistant to chemicals, drying, and mechanical stress -- not heat resistant
Card Set
Microbiology Unit 2 - Cells
Exam 1 Review