BIOL 223 Membrane Potentials - 2

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  1. An ion channel which flows towards the gradients and does not require an energy input is a:
    passive channel
  2. An ion channel which goes against the gradient and requires ATP is known as an:
    active channel
  3. True or False: Leak channels are specific to certain ions.
  4. Are leak channels mostly open or mostly closed?
    mostly open
  5. Will ions move down or away from their respective gradient through a leak channel?
    towards, or down, the gradient
  6. List the four types of passive ion channels discussed in class.
    • leak channels
    • mechanically gated channels
    • ligand-gated channels
    • voltage-gated channels
  7. What causes mechanically-gated channels to open?
    pressure being applied to the cell
  8. When pressure is removed from a cell, the mechanically-gated ion channels will:
  9. True or False: Ions will flow down the concentration gradient through mechanically-gated channels.
  10. What causes ligand-gated ion channels to open?
    the binding of specific neurotransmitters to receptor sites
  11. What must occur for a ligand-gated channel to close?
    removal of the neurotransmitter from the receptor site
  12. List the two primary structural compenents of a voltage-gated ion channel.
    • activation gate
    • inactivation gate
  13. A change in the potential of a cell membrane affects which type of passive ion channel?
    voltage-gated channels
  14. Why do active ion channels require ATP?
    because they go against, or up, the concentration gradient
  15. The sodium/potassium pump requires one ATP to pump _______ out of the cell against the gradient.
    3 sodium
  16. The sodium/potassium pump requires one ATP to pump _______ potassiums_______ the cell, against the gradient.
    two, into
  17. Small changes in potential that makes the membrane more or less negative are known as:
    local potentials
  18. Will making the membrane potential more negative increase or decrease the polarity of the cell?
    increase the polarity
  19. Does an increase in cellular polarity have a stimulatory or inhibitory effect on the cell?
    inhibitory effect
  20. Will making the membrane potential less negative increase or decrease the polarity of the cell?
    decrease the polarity
  21. The decrease in polarity of a cell will have an _______ effect.
  22. List the five causes of local potentials discussed in class.
    • ligand binding
    • mechanical stimulation
    • temperature changes
    • voltage changes
    • spontaneous change in permeability
  23. Small changes in potential that die out and do not result in a change of cellular activity is known as:
    decremental conduction
  24. When local potentials are larger or have additive effects that result in a change in cell activity, it is an example of:
    summation of local potentials
  25. True of False: A local potential will always result in a change in cellular activity.
    False - what happens after a local potential is determined by the size of the potential
Card Set:
BIOL 223 Membrane Potentials - 2
2011-10-31 00:02:16
anatomy physiology membrane potentials

Study Cards for Membrane Potentials BIOL 223 CSN
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