neurobio 6 ch 4 of Purve's book: ion channels and transporters part 1 (toxins patch clamp pore loo

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neurobio 6 ch 4 of Purve's book: ion channels and transporters part 1 (toxins patch clamp pore loo
2014-03-16 09:37:42
neurobio Purve book ion channels transporters part toxins patch clamp pore loop selectivity filter
neurobio 6 ch 4 of Purve's book: ion channels and transporters part 1 (toxins, patch clamp, pore loop, selectivity filter)
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  1. what are the four ways that the patch clamp method may be used?
    cell-attached recording, whole-cell recording, inside-out recording, outside-out recording
  2. what is cell-attached recording
    in this configuration, the pipette is attached to the surface of the cell membrane. The intracellular chemicals can't be controlled in this setup.
  3. what is whole cell recording
    in whole cell recording, the pipette is continuous with the cell cytoplasm. This arrangement allows measurements of electrical potentials and currents from the entire cell. one can also control the cytosolic contents of the cell with this setup
  4. what is inside out recording?
    when the pipette is attached to the membrane, the pipette is then pulled away, tearing a patch of the membrane off. This arrangement makes it possible to change the medium to which the intracellular surface of the membrane is exposed. Thus, the inside out configuration is particularly valuable when studying the influence of intracellular molecules on ion channels function
  5. what is the outside out recording technique>
    if a pipette is retracted while it is in the whole cell configuration, the membrane patch produced has its extracellular surface exposed. This arrangement is optimal for studying how channel activity is influenced by extracellular chemical signals such as neurotransmitters.
  6. what type of cell was used to understand ion channel functions?
    Xenopus oocytes
  7. what is the largest and most diverse class of ion channels?
    potassium channels
  8. what does electrogenic mean?
    generating a membrane potential
  9. what structure creates membrane potential in the neuron?
    active transporters
  10. how were hodgkin and huxley's proposals about the characteristics of ion channels confirmed?
    they were confirmed by an approach called patch-clamping
  11. how have scientists understood the functional significance of the multitude of ion channel genes?
    they selectively express the genes in cultured cells r frog oocytes and then studied using patch clamp and other physiological techniques. channel genes can also be deleted from genetically tractable organisms, such as mice or fruit flies, to determine the roles these channels play in the intact organism.
  12. true or false, all sodium channels inactivate after being activated?
    false, a voltage sensitive Na channel that doesn't inactivate after being opened has been identified
  13. the different classes of K channels differ in their _____ and _________ properties
    activation and inactivation