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Name the membrane valves that open and close for potassium efflux and sodium influx?
Wiki User
∙ 13y ago
ion channels
Wiki User
∙ 13y ago
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The greater influx of sodium ions results in what of the membrane?
depolarization
A nerve impulse results from?
It results from the opening of voltage-gated sodium ion channels, causing an influx of sodium ions (influx of positively-charged ions), depolarizing the neuronal membrane.
What regulates which substances enter and leave a cell?
The plasma membrane. Carrier proteins and ion channels are parts of the plasma membrane, and aid in diffusion across concentration gradients, as most things don't freely move from one end of the cell membrane to the other. The Sodium-Potassium pump is a major ion channel in the plasma membrane, and regulates the intake of potassium and export of sodium (3 molecules sodium out, 2 molecules potassium in.)
What is a brief description of the action of the sodium-potassium pump?
The sodium-potassium pump is a transmembrane protein in a cell membrane. It keeps large concentrations of sodium ions outside the cell, and potassium ions inside the cell. It does this by pumping the sodium ions out, and the potassium ions in.
Is the Sodium Potassium pump located on the apical membrane?
Sodium Potassium pumps are located on your body cells. This pump is used as a type of active transport to let these ions into and out of your cell.
Does action potential involve the influx of negative ions to depolarize the membrane?
No. The negative ions stay within the cell (neuron).An action potential begins (rising phase) with an influx of sodium, a positive ion or cation. The rising phase ends (falling phase) with an efflux of positive ions (potassium). The membrane potential is stabilized again with the action of the ATP dependent sodium-potassium pump.
Binding of the neurotransmitters with muscle membrane receptors causes the membrane to become permeable to sodium resulting in the influx of sodium ions an what of the membrane?
depolarization
When hinding of the neurotransmitters with muscle membrane receptors causes the membrane to become permeable to sodium resulting in the influx of sodium ions and what membrane?
action potential of the sarcolemma(the membrane)
The greater influx of sodium ions results in what of the membrane?
depolarization
Describe the events occurring in the cell membrane that permit the conduction of an impulse?
When a nerve impulse is conducted, the neuronal cell membrane undergoes changes in electrical potential. This starts with a rapid influx of sodium ions into the cell through voltage-gated sodium channels, depolarizing the membrane. This depolarization triggers the opening of adjacent sodium channels, resulting in an action potential that travels along the membrane. After the impulse passes, the sodium channels close, and potassium channels open, allowing potassium ions to exit the cell and restore the resting potential.
Why is there a resting membrane potential across the cell membrane?
sodium/potassium pump
Period during which potassium ions diffuse out of the neuron's membrane?
sodium-potassium pump
Drugs that decrease membrane permeability to sodium are used as what?
Drugs that decrease membrane permeability to sodium are used as local anesthetics. These drugs block the sodium channels and prevent NA+ from entering the cell. NA+ influx is important to dipolarize the membrane.
What form of cellular transportation helps human cells maintain their sodium and potassium concentration?
The sodium/potassium pump, the sodium leak channel and the potassium leak channel.
What is the role of ATP in sodium potassium pump?
transport across the membrane
What is the role of ATP in sodium-potassium pump?
transport across the membrane
Where does the sodium potassium release potassium ions?
The "fast" voltage-gated sodium channels open at -55 mV and close at about +60 mV. I found your question by attempting to find an answer to its second part which is "when [do]...potassium channels open..." and I have yet to find the answer to this myself! There are lots of graphs in physiology books which indicate it is at a voltage very close to that of the sodium channel but I have yet to find an actual figure! The important thing to know is that the potassium channels open at a similar time but are much slower at allowing potassium to flow out of the cell. The effect is that the influx of sodium rapidly brings the resting membrane potential from it's threshold potential of -55 mV to its peak of about +60 mV, at which point they close and become refractory. The slower potassium efflux then "catches up" and brings the membrane potential back down towards its resting value and actually causes a small over-shoot known as hyperpolarisation. The net change in cytosol concentration of the ions is minimal and quickly reversed by the magnificent Sodium-Potassium-ATPase. If you come across the answer to the opening voltage of the potassium channels, please let me know!
