BIOL 2160 Study Guide - Midterm Guide: Resting Potential, Fluid Mosaic Model, Fluid Compartments
Document Summary
Fluid mosaic model phospholipids move around like a liquid, mosaic made up of many different things. The membrane is non-polar: anything polar cannot pass through the membrane. Small or non-polar molecules can freely diffuse across the membrane. Large or polar molecules need carrier proteins to move across membrane. Cha(cid:396)ges (cid:373)ole(cid:272)ules (cid:272)a(cid:374)"t (cid:272)(cid:396)oss (cid:449)ithout help of othe(cid:396) p(cid:396)otei(cid:374)s (cid:374)o si(cid:373)ple diffusio(cid:374), so io(cid:374) (cid:272)o(cid:374)(cid:272)e(cid:374)t(cid:396)atio(cid:374)s do(cid:374)"t e(cid:448)e(cid:374)tuall(cid:455) even out. Sodium and potassium (k+ and na+) basically control resting membrane potential of all cells: always much more sodium outside the cell than inside, always much more potassium inside the cell than outside. Driving force 3 types: difference in energy across a membrane. + environment inside the cell repel + charges: all negative membrane potential more negative inside the cell than outside. Chemical force wants sodium to go into the cell, but electrical force wants sodium to leave the cell.