Membrane penetration rates of methanol and ethanol

[aboynamedsooie]

Does methanol penetrate a plant cell membrane faster than ethanol? Why or why not?

I know smaller molecules--which would be methanol in this case--usually penetrate the membrane more easily than larger molecules, but there's also lipid solubility to account for in this case. Also, why does water penetrate more quickly than the alcohols?

[MisterATP]

Water penetrate the membrane more quickly than alcohols because of integral proteins - aquaporins. And they are specific for only water molecules. Of course, water can move through membrane directly. It is because of special membrane structure (saturated and unsaturated fat acids, cholesterol) and conditions under which are the membrane (for example temperature).

First question is pretty difficult. I think there you need to look which of these two alcohols are more similar to water. Methanol is smaller then ethanol, but hydrogen bonds are weaker then in ethanol. You should find out the size/polarity value of each alcohol or something like that.