Transport Across Membranes

Question 1

Why do you blot dry a potato cylinder in an experiment?

Answer 1

Due to the fact that the water on the surface of the potato cylinder will affect the mass of the potato cylinder when it is reweighed and you are only wanting to find water/mass gain/loss.
Also the water on the surface is not the same for each potato cylinder as it can change so you wouldn’t know how much water to remove off after you have weighed it so it can’t be a fair test so it would be easier to just blot it dry to get rid of the water.

Question 2

What type of molecules move across membranes by simple diffusion?

Answer 2

Non-polar
Small
Lipid-soluble

Question 3

What type of molecules move across membranes by facilitated diffusion?

Answer 3

Polar

Large