Membrane Transport II Flashcards
(17 cards)
what determines the selectivity
of an ion channel?
diameter and shape of the ion channel, chraged amino acids lining the chanel
what are the differences between
ion channels and transporters?
-ion channel transport molecules across membranes much faster than transporters
which type of ion channels
plays a major role in setting the resting membrane potential?
K+ leak channels
True of False: ion channels do not remain open all the time.
true
Which of the following ion channels plays a major role in determining the rest
membrane potential?
A. Na+ channels
B. K+ channels
C. Ca+ channels
D. Cl+ channels
B. K+ channels
Q: what are the primary
ways ion channels can
be opened?
mechanical force
binding of a ligand
membrane potential
Q: True of False: Mechanically-gated channels in stereocilia of hair cells open in response
to sound-induced vibrations, converting mechanical stimuli into electrical signals.
true
Q: what part of a neuron is used to pass signals to its target cells?
the axon
Q: what is action potential?
an explosion of electrical activity that propagates along the axon as a wave
True or False: an inactivated
Na+ channel can reopen if
the cell membrane is further
depolarized.
false
Q: why action potentials propagate
only in one direction?
Na+ channel inactivation prevents action from spreading backwards
Q: how do voltage-gated Na+ and K+ channels change
their states during the course of an action potential?
-Na+ channel goes from closed to open to inactivated to closed
-K+ channel is first closed then opened then closed again
If Na+ channels are opened in a cell that was previously at rest, how will the
membrane potential be affected?
A. The membrane potential is not affected by Na+.
B. It becomes more negative.
C. It becomes less negative.
D. It is permanently at rest.
B. It becomes more negative.?
Q: True or False: activation of voltage-gated Ca2+
channels causes neurotransmitter release, converting
a chemical signal into an electrical signal.
True
Q: True or False: the same neurotransmitter can cause either an inhibitory or an excitatory
effect on its target cells, depending on the type of receptor it binds to on the target cell
True
Q: what is optogenetics?
light-gated ion channels from green algae can be used to to transiently activated or inactivate neurons in living animals
The depolarization of the nerve-terminal plasma membrane triggers the secretion of
neurotransmitters by opening which of the following?
A. Voltage-gated Na+ channels in the plasma membrane
B. Voltage-gated K+ channels in the plasma membrane
C. Transmitter-gated Ca2+ channels in the plasma membrane
D. Voltage-gated Ca2+ channels in the plasma membrane
C. Transmitter-gated Ca2+ channels in the plasma membrane
