ANSC 3301 Lecture 11: 28 January
Document Summary
Extracellular fluid has higher water concentration so moves into the cell and swells. The electrical force influences the movement of positive and negative charges. Force increases as the distance of separation between charges decreases. Separation of positive (outside) and negative (inside) charges along the membrane surface results in a potential difference (or voltage difference) that affects ion movement across the membranes of excitable cells. The magnitude of ion flux across a cell membrane required to make a significant change in membrane potential is extremely small. No charge in bulk solution or extracellular media! Electrochemical equilibrium: when the chemical gradient and electrical gradient are equal in magnitude. Voltmeter: how we measure the potential difference across the lipid bilayer. This occurs because there are different concentrations inside and outside the cell. Sodium is high outside, potassium is high inside (sodium-potassium atpase) This is the engine of your cell to keep your cells alive.
