ISCI 2A18 Study Guide - Final Guide: Capacitor, Cell Adhesion Molecule, Endoplasmic Reticulum
6 Dec 2016
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Document Summary
Transporters selective, active transport, can pump against gradient, driven by atp, concentration gradient, ph, speed limited by protein conformational change (slower), ex. Channel selectivity polar groups in pores shift selectivity towards cations or anions, pore size allows larger or smaller ions to pass. Gating conformational change in subunits allows the pore of an ion channel to open/close, 3 ways: Ligand activated by binding of signaling molecules (extracellularly or intracellularly) Voltage activated by changes in membrane potential. Stretch activated by physical deformation of cell membrane. Na+ permeability decrease will not have much effect (permeability is already very low) Decrease of both na+ and cl- permeabilities vm will equal k+ eq"m potential, which is negative. Vm with addition of kcl k able to pass through the membrane more easily, will depolarize membrane (outside concentration of k+ greater than inside, reverses the ratio in the equation) Vm with addition of nacl cl- will have a small effect on membrane potential.
