BMS02-1048 Electrochemical Equilibria Flashcards
Which 2 forces act on ions?
Concentration gradient and electrical gradient, sometimes there are balanced so the con pushing K out is the same as the force pulling K in
How can the equilibrium potential be found?
From the Nernst equation if the conc grad value is known
Nernst equation
E = RT/zF x ln (Conc out/Conc in)
E
Equilibrium potential for the ion
R
Universal gas constant
Z
Valency (charge) on ion
F
Faradays constant
What is the concentration gradient?
Store of potential energy to perform osmotic work
How to calculate the gradient?
Conc out/Conc in
What does osmotic potential depend on?
Number particles in solution and their kinetic energy
Osmotic work is stored as…
Potential energy by the concentration gradient
Osmotic work=
RT x ln (Conc out/Conc in)
Voltage is…
Measure of the work done in separating the ions
What is the unit of charge?
Coulomb
Electrical potential difference between 2 points is…
Work that must be done to move one coulomb of charge from one point to another
Voltage =
Joule / Charge
What is potential energy of charge?
1 volt when 1 joule of work is done moving 1 coulomb between 2 points
What are the units of electrical and osmotic work?
Joules/mole
Z =
Valency
How to calculate how many coulombs of charge 1 mole of ion can carry?
Valency x Faradays constant
Electrical work=
Potential difference (E) x Valency (z) x F
How is the Nernst equation written for monovalent ions?
E = 58 x log (Conc out/Conc in)
What are the units for RxT/zxF?
Joules per coulomb so its expressed in volts
Patch clamping
Electrode sealed to cell surface
