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Which of the following statements is true regarding the resting potential of a neuron?

1) It is more positive than the resting potential.
2) Voltage-gated potassium channels begin to close.
3) The membrane begins to hyperpolarize.
4) Threshold for a typical neuron is approximately -30 mV.
5) Voltage-gated potassium channels begin to open.

User Kederrac
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1 Answer

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Final answer:

Regarding the resting potential of a neuron, voltage-gated potassium channels begin to open is the true statement. The resting membrane potential is maintained by the selective ion movement through channels and sodium-potassium pumps, creating a net negative charge inside the cell.

Step-by-step explanation:

The statement that is true regarding the resting potential of a neuron is: Voltage-gated potassium channels begin to open. During the resting state of a neuron, the inside of the cell is appoximately 70 millivolts (-70 mV) more negative compared to the outside. This state is caused by the different concentrations of ions inside and outside the cell, which is maintained by sodium-potassium pumps that bring two K+ ions into the cell and remove three Na+ ions out of the cell.

The resting membrane potential is dominated by the movement of K+ ions, where more potassium leaves the cell than sodium enters due to a higher number of potassium leakage channels compared to sodium leakage channels. Consequently, the inside of the cell maintains a net negative charge. The aforementioned pump uses one molecule of ATP for each cycle to maintain this resting potential.

During an action potential, once the threshold potential is reached, voltage-gated Na+ channels open, leading to depolarization. However, shortly after reaching a peak potential (around +40 mV), voltage-gated K+ channels also open, allowing K+ to exit the cell, bringing the membrane potential back to its resting state in a process called repolarization. If any event causes K+ to leave the cell, it would cause hyperpolarization, making the interior of the cell even more negative than the resting potential.

User Srj
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