membrane permeability Flashcards
1
Q
name 3 factors that affect membrane permeability
A
- temperature
- pH
- use of a solvent
2
Q
how does temperature affect membrane permeability?
A
- high temperature denatures membrane proteins
- phospholipid molecules have more kinetic energy and move further apart
3
Q
how does pH affect membrane permeability?
A
changes tertiary structure of membrane proteins
4
Q
how does use of a solvent affect membrane permeability?
A
may dissolve membrane
5
Q
outline how colourimetry could be used to investigate membrane permeability
A
- use plant tissue with soluble pigment in vacuole. tonoplast and cell surface membrane disrupted = ↑ permeability = pigment diffuses into solution
- select colourimeter filter with complementary colour
- use distilled water to set colourimeter to 0. measure absorbance / % transmission value of solution
- high absorbance / low transmission = more pigment in solution
