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2.8

  1. what is the backbone of the plasma membrane made off?
    • phospholipids
    • *lipid bilayer
  2. plasma membrane structure- does it require energy to create the arrangement of the lipids on the membrane?
    no
  3. plasma membrane structure- how are the phospholipids oriented on a plasma membrane ? (2)
    • -phosphate group is facing the cytosol and extracellular fluids
    • *the polar side

    -non-polar side is facing the inside of the membrane
  4. plasma membrane structure- description of cholesterol
  5. plasma membrane structure- what does cholesterol do?
    • stiffens the plasma membrane
    • *necessary for the integrity of plasma membrane
  6. plasma membrane structure- 2 types of membrane proteins
    -integral

    -peripheral
  7. plasma membrane structure- (membrane proteins) what is the function of integral proteins?
    often function as channels
  8. plasma membrane structure-(membrane proteins) where are they located?
    they are embedded in membrane
  9. plasma membrane structure-(membrane proteins)how do peripheral proteins function?
    as receptors or enzymes
  10. plasma membrane structure-(membrane proteins) where are the peripheral proteins lcoated?
    • internal or external aspects of membrane
    • *they do not go across the membrane
  11. what is the function of the membrane dependent on?
    the types of proteins that are on it
  12. plasma membrane structure) what are the 2 ttypes of carbohydrate attchments?
    -glycolipid

    -glycoprotein
  13. plasma membrane structure) what is a glycolipid?
    carbohydrate on a lipid
  14. plasma membrane structure) what is a glycoprotein?
    carbohydrate on a protein
  15. plasma membrane structure) where are carbohydrate attachments usually located?
    external surface
  16. plasma membrane structure) what does a carbohydrate attachment do?
    contribute to the polarity for that side of the membrane
  17. plasma membrane structure) what is the function of lipid rafts?
    cell signaling
  18. plasma membrane structure) what does a lipid raft consist of? (2)
    -sphingolipids

    -cholesterol
  19. plasma membrane structure) what percent fo lipid rafts make of plasma membrane?
    20%
  20. specialized membrane structures) for what structure is microvilli important for?
    absorptive cells
  21. specialized membrane structures) what is the microvilli core made up off?
    • actin
    • *microfilament
  22. membrane-membranes adhesions) what 2 things make up glycocalyx?
    glycoproteins and glycolipids
  23. membrane-membranes adhesions) what do glycocalyx help with and why?
    they are able to interact with a neighboring plasma membrane bc they are polar
  24. membrane-membranes adhesions) in what fashion do wavy contours fit?
    tongue and groove action
  25. membrane junctions) where is there an abundancy of tight junctions?
    epithelium cells
  26. membrane junctions) description of tight juncntions?
    fused proteins molecules in adjacent membranes
  27. membrane junctions) functions of tight junctons? (3)
    -protective

    -does not allow material to come in between the cells

    -holds adjacent cells togther of the same tissue
  28. membrane junctions) where do tihgt juncitons tend to be located?
    • towards the apical
    • *it faces teh lumen or exterior
  29. membrane junctions) what are desmosomes made up off/ (2)
    -linker proteins

    -keratin filaments
  30. membrane junctions) fucntions of desmosomes?
    • provide integrity
    • *helps to hold adjacent cells together
  31. membrane junctions) where are they common in?
    in cells that are exposed to torsion
  32. membrane junctions) what type of cytoskleton do desmosomes contain?
    intermediate fillaments
  33. membrane junctions)description of gap junctions
    proteins form hollow passageways between cells
  34. membrane junctions) what do gap junctions allow?
    • materials to flow between cells (usually ions)
    • *quick commmunication between cells and action potential propagaiton
  35. 3 functions of plasma membrane
    -transport processes

    -cell to cell adhesion to form tissues

    -communication
  36. transport processes) passive transport- what is simple diffusion?
    • substances will move from an area of high concentration to low concentration
    • *bc of the tendency of molecules to randomize
  37. transport processes) passive transport- what is osmosis?
    diffusion of water molecules from a high concentration of water to an area of low concentration of water
  38. transport processes) a solution with a high osmolarity is one whcih...
    has a high particle concentration that attracts water
  39. what does osmolarity refer to?
    number of particles per liter
  40. what do osmolatity refer to?
    number of particles per kilogram or weight of a solution
  41. transport processes) passive transport- what is fascilitated diffusion?
    • involves the presence of protein transport proteins
    • *particles still move from high to low concentraton but channels make it easier to cross
  42. transport processes) passive transport- what is filtration?
    • water and solutes pushed through a membrane
    • *high pressure ot low pressure
  43. pressure changes- Osmotic
    pressure that resists further water entry into a chamber due to osmosis

    *** high osmolatity of a solution means that it will have a high osmotic pressure therefore more water that will be drwan in to that chamber before you reach equilibrium
  44. pressure changes- hydrostatic
    • pressure that is exerted by fluid on the walls of a chamber that enclose it
    • *blood pressure
  45. what is isotonic?
    • no net water movement
    • *will retain its shape
  46. what is hypotonic?
    • solution surrounding the cell is less concentrated than inside
    • *water will rush from outside to inside
  47. what is hypertonic?
    • soluiton outside of cell is more concentrated than inside
    • *water will move out
  48. active processes) what is  primary active transport?
    • moves molecules opposite to diffusion gradient
    • *requires energy
    • **can move 2 molecules at once in either same directions or opposite
  49. active processes) what are 2 types of primary  active transport?
    -symport

    -antiport
  50. active processes) primary active transport- symport
    2 molecules are moved at the same direction using primary active transport
  51. active processes) primary active transport- what is antiport?
    moves 2 molecules in opossite directions
  52. active processes) secondary transport- what is it?
    -after concentration gradient has been formed from primary active transport, the substance that was transported may diffuse and drag along another molecule
  53. vesicular active transport) what is exocytosis?
    vesicles carry molecules to the plasma membrane then fuse and excrete the molecules to the exterior
  54. vesicular active transport) endocytosis- what is phagocytosis?
    plasma membrane engulfs a particle that is outside of cel and brings it inside via vesicle transport

    *immune cells
  55. vesicular active transport) endocytosis- what is pinocytosis?
    • abosrption of a liquid along with the nutrients dissolved in it.
    • *vesicles bring the liquid along with the nutrients into the cell
  56. vesicular active transport) endocytosis- what are receptor mediated endocytosis?
    -receptor is located on the plasma membrane

    -membrane that binds with a particular molecule enduces endocytotic vesicles to bring the moelcules inside
  57. what is the main role of tight junctions?
    prevent invasion
  58. what do desmosomes prevent?
    cells from separating
  59. cell-cell adhesion and interaction- what areglycocalyx
    carbohydrate groups on membrane
  60. cell-cell adhesion and interaction- 2 things glycocalyx do?
    -anchoring

    -migration and signaling
  61. cell-cell adhesion and interaction- glycocalyx  what two movements are they involved in?
    -movement of cells during development and

    - of certain immune cells along tissues
  62. cell to environment interaction) what is a ligand?
    • environmental substance
    • *hormone, NT, drug
  63. cell to environment interaction) what happens when a ligand binds to a receptor?
    results in change of the metabolic activity of that cell
  64. cell to environment interaction) types of receptors- function of catalytic proteins
    when ligand binds, it causes the receptors to catalyze a reaction

    *often are enzymes
  65. cell to environment interaction) types of receptors- function ofchannel-linked receptors
    transmembrane (integral) proteins which open and close in response to a specific signal

    *controls entrance/exit of specific substances
  66. cell to environment interaction) types of receptors- where are channel linked receptors usually found in?
    nervous system
  67. cell to environment interaction) types of receptors- how do g-protein linked receptors work?
    \utilize assistance of g proteins to effect signal and create a cascade of events to finalize cellular event
  68. cell to environment interaction) types of receptors- is a second messenger involveed in g protein linked receptors?
    yes
  69. cell to environment interaction) types of receptors- description of how secondary messengers work
    -pass message from membrane protein to intracellular protein which will execute the command from the original ligand

    *this reaction would not have occurred had the ligand not binded to the receptor and gave the mesasge to it
Author
efrain12
ID
240527
Card Set
2.8
Description
membrane structure and function
Updated

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