HMB200H1 Lecture Notes - Lecture 3: Nernst Equation, Resting Potential
Document Summary
Sensory world: created by activation of sensory receptors. When channels open, become permeable to ions. Action transport of ions can move them against concentration gradients. Because if molecules were allowed to allowed, would flow down concentration. Equilibrium is not a static state, equal movement inside and out. Diffusion: movement of a substance from an area of higher concentration to an area of lower concentration through random motion. Seems to act independently for each substance. Because solvent molecules greatly out-number solute molecules. Differences in concentration of a substance among regions of a container causes diffusion from an area of higher concentration to an area of lower concentration. Seem to act independently for each substance. Differences in change between 2 regions that allows a flow of current if the two regions are connected. Ions will move down a charge gradient from an area of higher charge to an area of lower charge. Movement from concentration gradient = voltage gradient.