BIOC32H3 Lecture Notes - Lecture 2: Potential Energy, Resting Potential, Body Fluid
Document Summary
Resting membrane potential (ion composition of the body fluids: net charge on most proteins is negative, fig. 1: phosphorylated ions are membrane impermeable (po4-3 ; proteins: fig. 2: if equal amount of all permeable ions are both in and out of the cell. Right now, there are more negative charged ions in intracellular = charge imbalance. Neither body fluid is electrically neutral: fig. 3: then, the ions have shifted to gain equilibrium = donnan equilibrium. Now there are more ions inside of the cell, compared to outside and now there is an osmotic gradient which causes water to come inside the cell (hypoosmotic inside cell); causes cell to swell and burst. Nka pumps more ions out then in, allowing for better osmotic balance- and net outward movement of + charge (nka accounts for 30% of bmr: fig. 5: now, net movement of + out, causes - charged ions to diffuse out too causing + ions coming into cell.
