NROSCI 1000 Lecture Notes - Lecture 3: Resting Potential, Lipid Bilayer, Osmoregulation
Document Summary
Flows from high to low potential/charge (expressed in volts) Provide path for ions to flow through membrane. Electrical/membrane potential between inside and outside of cell. Inside is -70 mv relative to outside. Solutions inside and outside the neuron must be electrically neutral. The concentrations of intracellular/extracellular molecules must be in osmotic balance. Concentration of solute particles: inside = outside. No net flux of ions across membrane. Ions enter/leave neuron at the same rate. Balance of diffusive force and electrical force. Ions that contribute to resting membrane potential: na+, k+, cl-, a- (proteins) Concentration of na+ and cl- is greater outside cell. Concentration of k+ and a- (protein) is greater inside cell. Promote equal distribution of ions across membrane. Diffusion force drives ions down the concentration gradient. Charge separation: voltage difference between inside and outside. Icf and ecf are neutral even when there is charge separation. Inside is negative with respect to the outside.
