CP5 Beetroot membrane Flashcards

1
Q

What are 2 factors that affect membrane permeability?

A
  • Temp.
  • Conc. of solvents (ethanol + HCl).
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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.
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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.
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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.
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4
Q

What is the effect of temp on membrane permeability?

A
  • Increased temp results in increased permeability.
  • Proteins in membrane denature + create gaps.
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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.
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