What does electrical current refer to in cellular terms?

Electrical current in cellular terms specifically refers to the flow of charged particles from one point to another. In biological systems, this typically involves the movement of ions, such as sodium, potassium, calcium, and chloride, across cellular membranes. This movement can be a result of various mechanisms, including diffusion and active transport, and is essential for many physiological processes, including the generation of action potentials in neurons and muscle contraction.

When ions move, they carry an electrical charge, which contributes to changes in the membrane potential and is fundamental to the communication between cells. For instance, during an action potential in a neuron, rapid influx and efflux of sodium and potassium ions create a wave of electrical current that enables the transmission of signals along the nerve fiber. This phenomenon underscores how electrical current works in the context of cellular activity, distinguishing it from other concepts such as the flow of oxygen, ion storage, or static charge, which do not directly relate to the definition of electrical current.