Physiology: diffusion, vesicular transport, osmolarity & tonicity

Question 1

what law does diffusion follow

Answer 1

Fick’s Law

Question 2

what 5 factors affect the rate of diffusion

Answer 2

surface area, membrane thickness, conc. gradient, lipid solubility and molecular weight

Question 3

describe how surface area would effect rate of diffusion

Answer 3

increase SA = increase rate of diffusion

decrease SA = decrease rate

Question 4

describe how membrane thickness would effect rate of diffusion

Answer 4

increase membrane thickness = decrease rate

decrease membrane thickness = increase rate

Question 5

describe how conc. gradient would effect rate of diffusion

Answer 5

increase conc. gradient = increase rate

decrease conc. gradient = decrease rate

Question 6

describe how lipid solubility would effect rate of diffusion

Answer 6

increase lipid solubility = increase rate

decrease lipid solubility = decrease rate

Question 7

describe how molecular weight would effect rate of diffusion

Answer 7

increase molecular weight = decrease rate

decrease molecular weight = increase rate

Question 8

briefly describe action of endocytosis in vesicular transport

Answer 8

“pinching off” and engulfing, content moves from extracellular fluid to internal membrane

Question 9

briefly describe action of exocytosis in vesicular transport

Answer 9

vesicle binds to plasma membrane then releases content into extracellular fluid

Question 10

briefly describe the action of pinocytosis in vesicular transport

Answer 10

cell engulfs particle with plasma membrane, along with extracellular fluid around the particle

Question 11

breifly describe the action of phagocytosis in vesicular transport

Answer 11

cell ‘eats’ particle by engulfing it with cell membrane, forming a phagosome in the internal membrane

Question 12

what is osmolarity

Answer 12

conc. of osmotically active particles in a solution

Question 13

what is tonicity

Answer 13

the effect a solution has on cell volume

Question 14

what does isotonic mean

Answer 14

no net movement, no cell volume change

Question 15

what does hypotonic means

Answer 15

water diffuses into cells, cell swells

Question 16

what does hypertonic mean

Answer 16

water diffuses out of cells, cell shrinks

Question 17

describe the relative salt conc. inside the cell and in the solution when it is hypertonic

Answer 17

solution higher salt conc. than inside cell

Question 18

describe the relative salt conc. inside the cell and in solution when its hypotonic

Answer 18

solution lower salt conc. than inside the cell

Question 19

describe the relative salt conc. inside the cell and in solution when its isotonic

Answer 19

equal salt conc. in cell and solution