Refer to the graph below The graph shows the action potentia

Refer to the graph below. The graph shows the action potential produced in the axon of a neuron before (dotted purple line) and after (solid red line) the neuron was exposed to a chemical agent. Based on the change in the action potential trace, how might the chemical agent have affected the neuron? The agent blocked voltage-gated sodium channels. The agent blocked voltage-gated potassium channels. The agent blocked voltage-gated calcium channels. The agent blocked voltage-gated potassium and sodium channels

Solution

The graph after the neuron was exposed to a chemical agent, is because the agent has blocked voltage gated potassium channels . In the graph of normal action potential, there is repolarization of the neuron due to opening of the voltage gated potassium channels i.e. potassium efflux which brings the membrane potential back to -90mV i.e resting membrane potential of the neuron.But in the second graph i.e. after the neuron was exposed to the chemical agent,there is no potassium efflux resulting in no repolarisation of the neuron membrane.