membrane transport Flashcards
properties influencing permeating membrane
solubility of the particle in lipid
size of particle
ficks law of diffusion
The magnitude of the concentration gradient
The surface area of the membrane across which diffusion is taking place
The lipid solubility of the substance
The molecular weight of the substance
The distance through which diffusion must take place
what generates an electrical gradient
a difference in charge between two adjacent areas
electrochemical gradient
chemical and electrical gradient
osmosis
net diffusion of water down its own concentration gradient through a selectively permeable membrane
aqua porins
water channels
where does water mvoe to in osmosis
an area of higher solute conc
osmolarity
the concentration of osmotically active particles present in a solution
tonicity
effect a solution has on cell volume
isotonic
no net movement no chnage in cell volume
hypotonic
water diffuses int cells; cell swellsh
hypertonic
water diffuses out of cell; cell shrinks
carrier mediated transport
Substance binds onto a specific carrier which undergoes a conformational change (shape change) which transports the substance.
primary actuve transoirt
Energy is directly required to move a substance against its concentration gradient.
secondary active transport
Energy is required, but it is not used directly to produce ‘uphill’ movement
