PHGY 214 Lecture Notes - Lecture 3: Ligand-Gated Ion Channel, Potassium Channel, Choline
Document Summary
Memb proteins: channels, carrier molecules, docking-marker acceptors, memb-bound enzymes, receptor sites, cell adhesion molecules (cams) Diffusion: passive mvmt of solute down its conc/electric gradient rate will be high if: big conc grad: high permeability, small molecules, short distance large memb area. Osmotic pressure: the force required to oppose osmosis: posm=r * t*[solute] where t is in kelvin increase [solute]= increase posm, hypoosmotic solution cell would swell hyperosmotic=shrink, water moves from high [solute] or posm. Passive transport: via carrier proteins facilitated diffusion down conc grad: slow b/c no e or pore. Primary active transport: pump proteins, uses e/atp to pump solute against gradient ex. Na+ and k+ atpase: electrogenic mvmt, 3 na+ out and 2 k+ in, no pore, major e drain. Transport max tm: due to limited # of transporters. Types of channels leak channels: voltage gated, mechanically gated: open due to stretching or mechanical deformation thermally gated channels: respond to changes in temp.