CP5 Beetroot membrane Flashcards
1
Q
What are 2 factors that affect membrane permeability?
A
- Temp.
- Conc. of solvents (ethanol + HCl).
2
Q
How is beetroot used to measure permeability of membranes?
A
- Higher permeability - more red pigment leaks out into solution in given time.
- Colorimeter can be used to measure absorbance ∴ conc. of pigment.
3
Q
Outline experiment to investigate affect of temp. on membrane permeability.
A
- Cut beetroot into 6 cylinders using a cork borer + scalpel.
- Weigh each cylinder.
- Heat 6 test tubes of water to different temps.
- Add a cylinder to each test tube.
- Leave each for 20 mins.
- Filter each solution into cuvette + measure absorbance.
4
Q
What are the safety hazards involved in using ethanol to measure membrane permeability?
A
- Irritant + flammable - keep away from naked flames + use eye protection.
- Keep scalpel away from fingers.
- Handle hot liquid w care.
4
Q
What is the effect of temp on membrane permeability?
A
- Increased temp results in increased permeability.
- Proteins in membrane denature + create gaps.
5
Q
What is the affect of ethanol on membrane permeability?
A
- Increased conc. leads to increased permeability.
- Ethanol emulsifies phospholipids in membrane causing gaps to form.