Principles of solute and water movement Flashcards
(30 cards)
how much of tbw is ecf
1/3
how much of tbw is icf
2/3
How much of ecf is intersitial fluid
75%
how much of ecf is plasma
25%
What ions are high/low in ECF
High:
Na
Cl
Ca
Low:
K
What ion are high/low in ICF
High:
K
Low:
Na
Cl
Ca
What can cross lipid bilayer
hydrophobic/ small /uncharged/ molecules
What cannot cross lipid bilayer
large/hydrophilic/charged molecules
Define diffusion
passive movement of solute from high to low concentration
What is faciliated diffusion
movement of a solute passively from high to low concentration through as protein channel
What is active transport?
movement of solute from low to high concentration requires ATP
How are large molecules moved?
endo/exocytosis need ATP
Define osmosis
movement of water from a region of lower solute concentrations to a region of higher solute concentration across a semi permeable membrane
What is an osmole?
measure of solutions ability to create osmotic pressure and therefore affect water movement
What is osmolality ?
concentration of a solution expressed in osmoles/kg water
What aquaporin is signalled by ADH?
2
If the permeability co efficient is larger the substance is..
permeable
if the permeability co efficient is lower the substance is..
impermeable
What is passive transport dependent on?
permeability co efficient
concentration gradient
How to proteins contribute to membrane permeability?
enhance rate of diffusion by increasing Km and Vmax
Passive or active transport is dependent on
concentration ratio
membrane potential
What is primary active transport?
ATP used directly
e.g. PMCA plasma membrane ca ATPase
What is uniport?
1 ion/molecule one direction
What is symport?
2 ion/molecules one direction