13 — Biological membranes, membrane transport, electric properties of membranes Flashcards
What is the permeability constant?
Give the equation describing the flux of material transported across a membrane due to concentration difference between two compartments separated by the membrane.
What does it mean that phospholipids are amphipathic molecules?
What are the possible forms of motion of a lipid molecule in a membrane?
What are the possible phase states of biological membranes?
What changes in the properties of the fatty acid side chains increase the transition temperature of a membrane?
How does cholesterol change the fluidity of lipid membrane?
What is the magnitude of the lateral diffusion constant of lipids and proteins in biological membranes?
Which methods can be used to measure the lateral diffusion of proteins in biological membranes?
For what kind of molecules is the permeability of biological membranes the highest?
How can membrane proteins be classified on their function?
What are the extra- and intracellular concentrations of Na+, K+ and Ca+ ions?
What is passive transport?
What is active transport?
What is primary active transport?
What is secondary active transport?
What is simple diffusion across biological membranes?
What is facilitated diffusion?
What are the properties or facilitated or carrier-mediated diffusion?
What kind of ion channels do you know based on their mode of activation?
What is the function of ionophores
How can ionophores be grouped according to the mechanism of ion transport?
List the factors contributing to the maintenance of resting membrane potential.
Write the Nernst equation.
What is the equilibrium potential of an ion?
Are the ions on the two sides of the membrane of a living cell in thermodynamic equilibrium? Why?
Describe the relationship between net fluxes of major permeating ions at the resting membrane potential.
Give the definition and unit of flux.
Give the Goldmann-Hodgkin-Katz equation.
Give the definition and unit of conductivity.
Give the current carried by ion x through the cell membrane if the membrane potential is Em.
Define the action potential and interpret the ionic basis of its generation.
How do the concentrations of Na+ and K+ in the intra- and extracellular spaces change during a single action potential?
What causes the abrupt membrane potential changes during an action potential in a neuron?
What is the role of the Na+/K+ ATPase in the membrane potential changes during a single action potential? Why?
What is the principle of voltage-clamp?
List the methods that can be used for measuring the membrane potential of living cells.
What kind of currents can be measured by patch-clamp?
What are the most important features of ion channels?
What is the range of the voltages corresponding to the R waves of an ECG?
Give the Einthoven-Waller rule and interpret the variables in the formula.
What is the meaning of an ECG curve in the case of unipolar and bipolar leads?
