Membrane Structure Flashcards
Example of Pores
Aqua Porins
Example of Channels
Ca2+ Chanel
Normally gated by volatage or ligands
Carriers
Nuclear Transfer Proteins
Can be Symporters or Antiporters
Examples of ATP dependent Transport
Na-K ATPase
Ficks Law
Describes Diffusion J = DA*(Cout-Cin)/X D = diffusion constant A = Area C = Concentration X = Thickness of Membrane
Permeability and How it relates to Fick’s Law
P = DA/X Ficks Law can be written as: J = P(Cout-Cin) Permeability is route, Concentration is driving force Permeability has Linear Trend J = PC
How is Glucose Affected by Electrical Gradient
Glucose is not affected by electrical gradient because glucose is uncharged.
Delta G
The Chemical and Electrical Difference
These are the two potential driving forces
Nernst Equilibrium Equation
E = -61/Z * log [X]in / [X]out Z = valence E = Membrane Potential - Value Indicates movement into of cell \+ Value indicates movement out of cell
Faraday Law
Delta G = RT ln [X]in / [X]out + F(Delta E) z
Water Transport
Always moves passively Moves through aqua porins Driving force is osmolarity or osmotic pressure Water moves to balance concentrations i.e. moves from lower [ ] to higher [ ]
Osmolarity
pi = (Sigma)(nCRT) Sigma = reflection coefficient [0-1] n = number of particles C = Concentration R = gas constant T = temp (kelvin)
If a cell has a concentration of 200 (anything) and is placed in a solution of 200 (anything) and the cell swells what can you say about the solution
The solution has a lower effective osmotic pressure since the water flows into the cell to balance the osmotic pressure
i.e. cell because hypotonic.
Movement between ICF and ECF
Uses Osmotic Pressure
Movement between intersitial space and into the plasma
Uses Oncotic Pressure
Takes into account [protein]
