Physiology: diffusion, vesicular transport, osmolarity & tonicity Flashcards
what law does diffusion follow
Fick’s Law
what 5 factors affect the rate of diffusion
surface area, membrane thickness, conc. gradient, lipid solubility and molecular weight
describe how surface area would effect rate of diffusion
increase SA = increase rate of diffusion
decrease SA = decrease rate
describe how membrane thickness would effect rate of diffusion
increase membrane thickness = decrease rate
decrease membrane thickness = increase rate
describe how conc. gradient would effect rate of diffusion
increase conc. gradient = increase rate
decrease conc. gradient = decrease rate
describe how lipid solubility would effect rate of diffusion
increase lipid solubility = increase rate
decrease lipid solubility = decrease rate
describe how molecular weight would effect rate of diffusion
increase molecular weight = decrease rate
decrease molecular weight = increase rate
briefly describe action of endocytosis in vesicular transport
“pinching off” and engulfing, content moves from extracellular fluid to internal membrane
briefly describe action of exocytosis in vesicular transport
vesicle binds to plasma membrane then releases content into extracellular fluid
briefly describe the action of pinocytosis in vesicular transport
cell engulfs particle with plasma membrane, along with extracellular fluid around the particle
breifly describe the action of phagocytosis in vesicular transport
cell ‘eats’ particle by engulfing it with cell membrane, forming a phagosome in the internal membrane
what is osmolarity
conc. of osmotically active particles in a solution
what is tonicity
the effect a solution has on cell volume
what does isotonic mean
no net movement, no cell volume change
what does hypotonic means
water diffuses into cells, cell swells
what does hypertonic mean
water diffuses out of cells, cell shrinks
describe the relative salt conc. inside the cell and in the solution when it is hypertonic
solution higher salt conc. than inside cell
describe the relative salt conc. inside the cell and in solution when its hypotonic
solution lower salt conc. than inside the cell
describe the relative salt conc. inside the cell and in solution when its isotonic
equal salt conc. in cell and solution
