Phospholipids differ in.txt

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Phospholipids differ in.txt
2013-06-06 01:25:13


principles of life
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  1. Phospholipids differ in
    chain length, degree of saturation, and kinds of polar groups present
  2. Two important factors in membrane fluidity
    lipid composition, temp
  3. lack hydrophobic groups and are not embedded in the bilayer
    peripheral membrane proteins
  4. are partly embedded in the phospholipid bilayer
    integral membrane proteins
  5. extends through the bilayer on both sides and may have different function in its external and transmembrane domains
    transmembrane protein
  6. plasma membrane carbs are located on the ____ membrane. they can serve as ___.
    outer; recognition sites
  7. A carb bonded to a lipid
  8. a carb bonded to a protein
  9. thsi type of transport does NOT require metabolic energy
  10. this type of transport DOES require metabolic energy
  11. types of passive transport
    simple diffusion and facilitated diffusion
  12. diffusion through the phospholipid bilayer
  13. diffusion through channel proteins r aided by carrier proteins
  14. speed of diffusion depends on these 3 factors
    diameter, temp, concentration gradient.
  15. ____ molecules do not pass through the bilayer. they are not soluble
    polar. they are hydrophilic and instead stay in the aqueous environment near the membrane
  16. diffusion of water across membranes
  17. during _________ water passes through special membrane channels
  18. this kind of solution has a higher solute concentration
  19. this kind of solutions have equal solute concentrations
  20. these kinds of solution has a lower concentration
  21. the internal pressure against the cell wall. preventing water from entering as it builds up
    turgor pressure.
  22. two ways of facilitated diffusion
    channel proteins and carrier proteins
  23. this is a type of channel protein- most are gated. and can be opened or closed to ion passage
    ion channels
  24. this opens when a stimulus caused the channel to change shape
    gated channel
  25. a chemical signal
  26. a ____ gated channel responds to its ligand
  27. a ______ gated chanenel opens or closes in response to a change in the voltage across the membrane
  28. water crosses membranes at faster rate than ______ diffusion
  29. water may ______ with ions such as Na+ as they pass through ion channels
  30. the faciliated diffusion sysetm can become _____ when all of the carrier molecules are bound and the rate of diffusion reaches its max
  31. ______ transport requires the input of energy to move substances against their concentration gradient.
  32. ______ transport is used to overcome concentration imbalances that are maintained by proteins in the membrane
  33. the energy source for active transport
  34. active transport is _____ and moves a substance against its concentration gradient.
  35. a substance moves in the durection of the ______
    cell's needs
  36. types of active transport
    primary and secondary
  37. this kind of acive transport involves hydrolysis of atp for energy
    primary active transport
  38. this kind of active transport used the energy from an ion concentration gradient, or an electrical gradient
  39. this is an important membrane protein that pumps sodium OUT of the cell and K in
    sodium-potassium pump
  40. one molecule of ATP moves ___ K and ____ na ions
    2; 3
  41. ______ active transport used energy that is regained
  42. secondary acive transport may begin with ______ of a few ions, or may involve ______ that transports both a substance and ions
    diffusion; carrier protein
  43. macromolecules are too big or too charged to pass through membranes, instead, they pass through
  44. To take up or secrete macromolecules, cells must use
    endocytosis or exocytosis.
  45. 3 types of endocytocis (brings into cell)
    phagocytosis, pinocytosis, receptor-mediated endycytosis.
  46. during _____, the membrane invaginates the molecules and forms a vesicle that separates fom the membrane
  47. during ____, part of the membrane engulfs a large particle of a cell
  48. during _____, (cellular drinking), small vessicles form, bring in fluids/dissolved substances
  49. receptor mediated endocytosis depend on _____ to bind specific molecules (their ligands)
  50. receptors are important membrane proteins locaed in
    coated pits
  51. cytoplasmic surace is coated by another protein
  52. when receptors bind to their ligands, the coated pit ____ and forms a _________
    invaginates; coated vesicle
  53. The clarhrin stabilizes the vesicle as it carries the _____ into the cyttoplasm
  54. Once inside, the vesicle loses its _____ and the substance is digested
    clathrin coat
  55. this process moves the materials out of the cell in vesicles
  56. in exocytosis, the vesicle membrane fuses with the ___________ and the contents are released into the cellular environment
    plasma membrane
  57. these kinds of signals affect the same cell that released them
  58. these kinds of signals diffuse to and affect NEARBY cells
  59. these kinds of signals travel to distant cells
  60. only cells with thte necessary receptors can respond to a signal. the ___ cell must be able to sense it and respond to it
  61. a signal transduction pathway involves a ___, a ____ , and a _____.
    signal, receptor, and response
  62. during _______ regulation, a signal molecule (ligand), fits into a three dimensional site on the receptor protein, causes it to change shape, and produces either a short or long term response.
  63. _______ receptors have ligands, such as estrogen, that are small or non polar and can diffuse across the membrane
  64. ______ receptors have large or polar ligands, such as insulin, that CANNOT diffuse and must bind toa transmembrane receptor at an extracellular site.
  65. _____ ____ ______, also known as GATED ___ _____ , change their three dimensional shape when a ligand bonds.
    ion channel receptors, gated ion channels
  66. ___________ receptors change their shape when a ligand binds
    protein kinase
  67. protein kinase catalyze the pholowing reaction:
  68. ligands binding to a ______ expose a site than can bind to a membrane protein (a _______ protein).
    g protein-linked receptors; g protein
  69. the ______ protein is partially inserted in the lipid bilayer and parially exposed on the cytoplasmic surface
  70. 3 subunits of g proteins
    receptor, GDP AND GTP (USED FOR ENERGY TRANSFER), and an effector protein to cause an effect in the cell.
  71. The g protein-linked receptor changes a GDP nucletide bound to the g protein for a higher enrgy
  72. signaling can initiate a ______ of protein interactions; the signal can then be ____ and_____ to cause different responses
    cascade; amplified; distributed
  73. a _____ messenger is an intermediary between the receptor and the cascade of responses.
  74. in fight or flight response, epinephrine activates the liver enzyme _______ __________.
    glycogen phosphorylase
  75. ______ enzyme can be activated by the membrane bound epinephrine in broken cells as long as parts are present.
  76. the molecule that delivers the messege from the 'first messenger', epinephrine to the enzyme.
    cyclic AMP (cAMP)
  77. in protein kinase pathway, ______ binds to its receptor and activates a G protein
  78. cAMP is produced and activates _________-it phosphorylates two other enzimes with opposite effects ____ & ______.
    Protein kinase A; inhibition; activation
  79. During _____, protein kinase A inactivates glycogen synthase through phosphorylation and prevents gluclose storage
  80. During ____ phosphorylase kinase is activated when phosphorylated and is part of a cascade that results in the liberation of glucose molecules.
  81. Signal trasductione ends when
    the cell responds
  82. 2 ways cells can alter the balance of enzymes
    synthesis or breakdown of enzyme & activation or inhibition of enzymes by other molecules
  83. 3 ways cell function changes in response to environmental signals
    opening of ion channels, alterations and gene expression, alteration of enzyme activities.
  84. What effect does caffeine have on the brain?
    similar structure to adenosine, so it bind's to adenosine's receptors (which cause drowsiness) and inhibits thems so alertness occurs