if you immerse your hand in distilled water for 15 min,will your cells lyse?Why or why not?

Answer 1

Well, I'm tempted to say "Try it and see!", but there is a way to know if it is safe beforehand.

First of all, only plants have "cell walls", so the above answer is not correct. Secondly, the phopholipid bilayer membrane is permeable to water, so that reason doesn't work either.

What does protect you is a very thin layer of oils (which are also called lipids) that protect your skin. Skin is naturally oily, and this oil forms a barrier that water does not cross easily. This is why over-washing your hands can cause them to dry out, as the oil is removed, and water can escape. Now, as to whether or not this oil would hold up to 15 minutes of immersion, I'm not entirely sure, but my guess would be "yes".

Drinking the water exposes your non-oil protected cells to the water, and this would be more problematic.

Answer 2

No, you have a lipid bilayer (cell wall) that actively controls movement of ions in and out of the cells. This would keep them from lysing.