A neuron is poisoned with the chemical ouabain which is an i

A neuron is poisoned with the chemical, ouabain, which is an inhibitor of the Na^+ - K^+ ATPase. Explain what would happen to the resting membrane potential (RMP) of the cell (will it depolarize, hyperpolarize or remain the same). In your answer, ^1 identify the three factors that determine RMP in a neuron, ^2 identify whether each factor causes membrane potential to be more or less negative, and ^3 explain whether or not ouabain would affect each factor.

Solution

Answer:

Ouabain is poisonous substance extracted from the plant( Strophanthus gratus), it is cardiac glycoside.In a cell, Ouabain inhibit the activity of the Na⁺/K⁺ ATPase.

Na⁺/K⁺ ATPase allows movement two Na+ into cell and three K+ out of the cell during ATP hydrolysis, due to movement of one extra positive charge (K+) from inside to out side , there is a development of the negative membrane potential, this is called as the resting membane potential, it is in resting condition, when there is continuous flow influx of Na+ and efflux of K+ .

The inhibition of Na⁺/K⁺ ATPase leads to depolarisation of membrane at least amount (5mV). If it is inhibited for long period, it may lead to zero membrane potential due to development of less negative.Na⁺/K⁺ ATPase regulates the membrane potential. finally inhibition of Na⁺/K⁺ ATPase leads to depolarization of the membrane.