GLOSSARY

Electrochemical Gradient is the driving force from concentration and voltage differences across a membrane, not concentration alone.

Ions move under both concentration and electrical forces; the electrochemical gradient combines these components. Membrane potential describes voltage across a membrane, not the muscle's food energy. Selective permeability and ion distribution both matter. This helps explain muscle excitation, but the existence of a gradient does not establish that an electrolyte supplement accelerates nerve signaling in an athlete already adequately supplied.

Sodium is mainly the extracellular cation and potassium mainly intracellular; chloride and other anions contribute to charge balance. Selective membranes, transporters and energy expenditure maintain these distributions. Blood concentration does not directly report muscle content. Movement between compartments may occur faster than changes in total stores and can affect a sample even without a corresponding dietary change.

Distinguish the cellular role of electrolytes from supplement outcomes; a transporter or enzyme does not prove extra intake improves sport.

An ion channel is a protein allowing selective ion movement along its driving force, with gating by voltage, chemical signals or stretch. It differs from an active pump and does not directly use ATP for each transported ion. Opening can rapidly change voltage; the outcome depends on ion, distribution and tissue, not simply the presence of sodium, potassium, calcium or chloride on a food label.