The inside of the cell membrane becomes negative at the time of an action potential.Group startsTrue or FalseTrue, unselectedFalse, unselected

Step 1: Break Down the Problem

The statement to evaluate is whether the inside of the cell membrane becomes negative during an action potential. To analyze this, we should understand the basic mechanics of an action potential, particularly in how the membrane potential changes.

Step 2: Relevant Concepts

1. Resting Membrane Potential: Typically, the inside of a neuron at rest is negative relative to the outside, usually around -70 mV.
2. Depolarization: When a neuron fires, there is a rapid influx of sodium ions ($Na^+$), which makes the inside of the cell more positive — this is called depolarization.
3. Repolarization: After peak depolarization, potassium ions ($K^+$) flow out of the neuron, which helps restore the negative membrane potential — this is sometimes referred to as repolarization.

Step 3: Analysis and Detail

During the initiation and propagation of an action potential:

• Initially, the inside of the cell becomes less negative (depolarizes) when $Na^+$ ions rush in.
• Following this, $K^+$ ions exit the cell, leading to a return to a more negative resting state — this is repolarization but does not mean that the cell interior remains negative throughout the action potential.

Step 4: Verify and Summarize

The statement in question is misleading. The inside of the cell becomes positive during the action potential peak; it does not become negative at this time. After the action potential, during the repolarization phase, the inside becomes negative again.

Final Answer

False – The inside of the cell membrane does not become negative during an action potential; it becomes positive due to sodium influx during depolarization.