Establishing Membrane Potential Flashcards
What is potential energy?
The ability to do work → gradient (difference between two points)
Gradient-driven flux requires?
- Gradient (concentration)
2. Carrier or pathway
Fick’s Law is used to find?
Net diffusional flux
Fick’s Law equation
Flux = DA(concentration difference / thickness of diffusion barrier)
Net diffusional flux depends on?
- Concentration gradient
- Area
- Coeffecient
Net diffusional flux coefficient accounts for?
- Molecular radius
- Solution viscosity
- Gas constant
- Temperature
Ohm’s Law is used to find?
Current (electrical flux)
Current is quantitative measure of?
Electrical flux
I represents?
Current
Ohm’s Law (2 forms)
Current = voltage / resistance
Current = voltage * conductance
Voltage is quantitative measure of?
Gradient
Conductance and resistance are quantitative measures of?
Pathway permeability
Unit of currents
Amps
Amps = ?
Coulombs / unit of time
Unit of voltage (gradient)
Volts
Unit of conductance
Siemens
“Driving force” refers to?
Voltage
g represents?
Conductance
g of pure water
Low
Adding salt to water has what effect on g?
Increases g
Adding a barrier to a solution has what effect on g?
g = 0
Making a barrier permeable has what efect on g?
Increases g
Minimum requirements to establish resting membrane potential
- Power source
- Charge carrier
- Conductive pathway
- Gradient
Nernst equation includes?
Concentration and electrical gradients (joins Fick’s and Ohm’s Laws)
Nernst equation can be used to describe?
- Systems at equilibrium
- Direction of flux in current conditions
- Membrane potential if membrane is only permeant to one ion
Concentrational gradient is proportional to?
Voltage (electrical gradient)
