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resting potential (A-Level biology) Watch

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    I was wondering if anyone would please be able to explain resting potential to me?

    the main thing that i find confusing is the permeability of the membrane - which is it more permeable to at resting potential?? and when does the permeability change (and how)??
    but also the general principles of resting potentials, and how an action potential changes this

    would be great if someone could just clarify this for me
    thank you!
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    (Original post by laurab2702)
    I was wondering if anyone would please be able to explain resting potential to me?

    the main thing that i find confusing is the permeability of the membrane - which is is more permeable to at resting potential?? and when does the permeability change (and how)??
    but also the general principles of resting potentials, and how an action potential changes this

    would be great if someone could just clarify this for me
    thank you!
    Potassium ions are permeable to the membrane so the ions can diffuse out the potassium pump
    Resting potential is -70mV
    Sodium ions electrochemical graidient is maintained due to the sodium potassium pump
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    (Original post by laurab2702)
    I was wondering if anyone would please be able to explain resting potential to me?

    the main thing that i find confusing is the permeability of the membrane - which is is more permeable to at resting potential?? and when does the permeability change (and how)??
    but also the general principles of resting potentials, and how an action potential changes this

    would be great if someone could just clarify this for me
    thank you!
    The resting potential is when the inside of the cell is like -70mv, so the Na+ And k+ channels are closed. An action potential is reached when the influx of Na+ increases( this causes depolarisation along the membrane which causes more influx of Na+ hence called the Postive feedback), the Na+ reaches the threshold and THEN an action potential is created. If the threshold isn't reached then you don't have an action potential. The threshold maybe around -50mv, then due to positive feedback you reach about +40mv and then your K+ opens and this now brings down the mv to about -75 which is hyperpolarisation.
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    At resting potential:
    - the sodium- potassium ion pump pumps 3 sodium ions out of the neuron for every 2 potassium ions pumped in ( this requires energy form ATP)
    - the membrane is permeable to potassium ions ( has the potassium ion channels are open) so potassium ions diffuse out of the neuron
    - the membrane is not permeable to sodium ions
    - this makes the outside of the neuron relatively positive compared to the inside

    when it changes:
    - A stimulus excites the neuron, causing sodium ion channels to open
    - So generator potential
    - if the threshold is reached more voltage gated sodium ion channels open
    - this depolarizes the neuron ( aka makes the the inside less negative)

    ( sorry if there are any spelling mistakes)
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    (Original post by en1)
    At resting potential:
    - the sodium- potassium ion pump pumps 3 sodium ions out of the neuron for every 2 potassium ions pumped in ( this requires energy form ATP)
    - the membrane is permeable to potassium ions ( has the potassium ion channels are open) so potassium ions diffuse out of the neuron
    - the membrane is not permeable to sodium ions
    - this makes the outside of the neuron relatively positive compared to the inside

    when it changes:
    - A stimulus excites the neuron, causing sodium ion channels to open
    - So generator potential
    - if the threshold is reached more voltage gated sodium ion channels open
    - this depolarizes the neuron ( aka makes the the inside less negative)

    ( sorry if there are any spelling mistakes)
    ah okay, fab - thank you, that makes sense
 
 
 
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