RP4-cell membrane permeability

Question 1

state two factors that affect membrane permeability

Answer 1

-temperature
-concentration of solvent (ethanol)

Question 2

how is beetroot used to measure the permeability of cell membranes

Answer 2

-higher permeability causes more pigment to leak out, into the surrounding solution
-colorimeter can be used to determine the absorbance and therefore the concentration

Question 3

outline the procedure used to investigate the cell permeability of beetroot

Answer 3

-cut beetroot into six equal cubes with a scalpel
-add each cube to a test tube with an equal amount of distilled water
-add to water baths at different temperatures from 30-80C
-leave for 20 mins
-filter each solution into cuvette and measure absorbance to calculate concentration using colorimeter
-could use ethanol at different conc. instead of temp

Question 4

what are the safety hazards associated with investigating cell permeability of beetroot

Answer 4

-Ethanol is an irritant and flammable so keep away from naked flames and away from skin and eyes, wear goggles
-scalpel, lacerations avoid cutting fingers
-hot liquid, burns so handle with care

Question 5

what are the effects of ethanol concentration and temperature on cell membrane permeability

Answer 5

-increased temperature or increased ethanol concentration both cause an increase in the cell membrane permeability