Question

2. If potassium channels in a neuron were blocked, would it be possible to produce an action potential? If so, describe the probable appearance of these components of a graph: threshold, rising phase, peak, falling phase, undershoot. If not, explain.

Answer 1

If potassium channels were blocked in a neuron, it would prevent the neuron from repolarizing and returning to its resting potential after the action potential's peak, likely resulting in disrupted neuronal signaling.

Step-by-step explanation:

If potassium channels in a neuron were blocked, it would severely impact the neuron's ability to produce an action potential. The action potential is an all-or-nothing event that involves specific steps including depolarization and repolarization of the neuron's membrane by the flow of ions through sodium and potassium channels.

The blockage of potassium channels would prevent the neuron from returning to its resting potential after depolarization has occurred, effectively disrupting the normal action potential phases. The rising phase of depolarization occurs when sodium channels open and Na+ ions enter the cell. If potassium channels are blocked, after reaching the peak, the neuron would not be able to repolarize properly because K+ ions cannot exit the cell to bring the membrane potential back down. This means that the falling phase and the undershoot would be absent or severely altered, and the neuron would likely remain depolarized for an extended period, unable to return to the resting potential and unable to fire another action potential during this time.