[Campbell Biology P.1121] According to Figure 48.10 and the "Visual Skills" prompt, why is th... | Practice Question

According to Figure 48.10 and the "Visual Skills" prompt, why is there a net ion movement across the membrane when the voltage-gated channel opens?

  • A: The channel actively pumps ions against their electrochemical gradient.
  • B: The channel creates a new electrical gradient that pulls ions across.
  • C: Ions move down their pre-existing electrochemical gradient.
  • D: The channel converts chemical energy into kinetic energy for ion movement.

Explanation

Voltage-gated ion channels open to allow ions to flow across the membrane. This movement occurs passively, driven by the pre-existing electrochemical gradient both concentration and electrical gradients across the membrane, leading to a net ion movement.