Exam 2: Functions, Nernst & Goldman Equation

What is the Nernst equation used for?

used to calculate the equilibrium potential for an ion based on the ratio of its extracellular and intracellular concentrations.

What factors are involved in the Nernst equation?

the gas constant (R), temperature (T), Faraday's constant (F), the charge of the ion (z), and the ratio of the extracellular to intracellular ion concentration.

What does the Goldman-Hodgkin-Katz equation calculate?

It calculates the membrane potential (Vm) based on the permeability and concentrations of Na+, K+, and Cl-.

What is the relationship between the conductance (gK and gNa) and membrane potential during the rising phase of an action potential?

the conductance of Na+ (gNa) increases, driving the membrane potential toward ENa.

What happens when the concentration of an ion outside the cell ([ion]out) is greater than inside the cell ([ion]in)?

the equilibrium potential (Eion) will be positive, as in the case of Na+

What is the relationship between conductance and membrane potential during the falling phase of an action potential?

the conductance of K+ (gK) increases, driving the membrane potential toward EK.

What happens to the equilibrium potential when the concentration gradient is zero?

Eion becomes 0 because there is no concentration gradient to drive ion movement.

Which protein is essential for maintaining the concentration gradient of K+?

The sodium potassium pump as it actively transports K+ into the cell and Na+ out.

What happens to equilibrium potential if the concentration gradient increases?

moves further from 0, as a larger gradient strengthens the electrochemical force driving ion movement.