Help on all please 18 What ions are important when calculati

Help on all please

18) What ions are important when calculating the resting membrane?

19) What are the differences between the Nernst equation and the resting membrane equation?

20) Is a cell’s membrane ever at rest? If not, how can one remedy the resting membrane equation?

21) What is a resting potential… a graded potenial… what is an action potenial?

Solution

The resting membrane potential is different from the equilibrium potential as it relies on the constant expenditure of energy for its maintenance. Unlike the equilibrium potential, the resting membrane potential is dominated by the ionic species in the system that has the greatest conductance across the membrane. For most cells this is potassium. As potassium is also the ion with the most negative equilibrium potential, usually the resting potential can be no more negative than the potassium equilibrium potential. The resting potential can be calculated using the concentrations of pottasium and taking into account concentration of other ions as for the equilibrium potential while also including the relative permeabilities of each ionic species. Under normal conditions, it is safe to assume that only potassium, sodium (Na⁺) and chloride (Cl) ions play large roles for the resting potential.