What is the term for the mechanism that alters ion flux across plasma membranes by opening or closing channels?

The mechanism that alters ion flux across plasma membranes by opening or closing channels is referred to as channel gating. This process is essential for controlling the movement of ions, such as sodium, potassium, calcium, and chloride, into and out of cells. Channel gating can occur through various mechanisms, including changes in voltage across the membrane, binding of specific ligands, or mechanical forces.

When ion channels are gated open, they allow specific ions to flow according to their electrochemical gradients, which is crucial for processes such as action potentials in neurons, muscle contraction, and neurotransmitter release. Conversely, when channels are gated closed, ion flow is restricted, which helps maintain the resting membrane potential and regulates other cellular functions.

The terms offered in the other choices refer to concepts that are related but distinct. Channel modulation involves the influence of various factors on the overall function of ion channels but does not specifically describe the mechanism of opening and closing. Ion regulation pertains to the maintenance of ion concentrations in the body but encompasses a broader range of processes beyond just channel activity. Electrochemical control implies a method of regulating ion movement based on electrical and chemical gradients but does not specifically address the physical action of opening and closing channels.