The depolarization phase is due to the opening and closing of Blank______ ion channels.Multiple choice question.enzyme-gatedvoltage-gatedligand-gated

Breakdown the Problem

1. We need to identify the type of ion channels responsible for the depolarization phase.
2. We have three options to consider: enzyme-gated, voltage-gated, and ligand-gated ion channels.

Relevant Concepts

1. Enzyme-gated channels: These channels open in response to the activation of enzymes but are not directly involved in the rapid changes that occur during depolarization.
2. Voltage-gated channels: These channels open in response to changes in membrane potential and are crucial during the depolarization phase of action potentials in neurons and muscle cells.
3. Ligand-gated channels: These channels open in response to binding of specific neurotransmitters or other molecules, involved in synaptic transmission rather than the rapid depolarization phase.

Analysis and Detail

1. During the depolarization phase of an action potential, the membrane potential becomes less negative due to the influx of sodium ions (Na⁺).
2. The opening of voltage-gated sodium channels allows Na⁺ ions to rush into the cell, leading to a rapid increase in membrane potential.

Verify and Summarize

1. The process of depolarization is predominantly mediated by the opening of voltage-gated channels, specifically voltage-gated sodium channels.
2. Therefore, the most accurate choice among the provided options for what triggers the depolarization phase is voltage-gated ion channels.

Final Answer

The correct answer is voltage-gated ion channels.