Flashcards in L3: Membrane Potentials Deck (7):
Describe the permeability of cell membranes to ions under normal circumstances when at rest.
Sodium ion permeability -membrane has low permeability when at rest
Potassium ion permeability - membrane is more permeable to potassium than sodium at rest
Calcium ion permeability - membrane has a low permeability at rest
Chloride ion permeability - membrane has moderate permeability when at rest
Compare the major types of ion channels present on the cell membranes of excitable cells.
Voltage gated: changes in voltage
Ligand gated: binding of specific molecules (ligands) to receptors
Modality fated: mechanical deformation
What is the Nernst equation and what is it used for?
E = 2.3 RT/F log Co/Ci
used to calculate membrane potential.
What is diffusion potential?
Is the potential difference generated across a membrane because of a concentration difference of an ion. Can only be generated if the membrane is permeable to the ion.
What is equilibrium potential?
Is the membrane potential where the net flow through any open channels is 0. At Erev the chemical and electrical forces are in balance.
What is electrical neutrality principle?
States that each atom in a stable substance has a charge close to zero
The sum of concentration of cations must be equal to the sum of concentration of anions