Question

Ok, can someone explain water potential to me? It's kinda confusing.

My notes say it's a solutes relative concentration to a solvent, which affects the rate of osmosis.

So, side A and side B have 20 ml of water (There is a semi-permeable membrane in between that only allows water through), side A has 5g of sugar and side B has 20g of sugar. That means since there is more sugar on side B the water to sugar ratio is lower so the water from side A will balance out the ratios between side A and B by moving across the membrane?

I understand that, but what does that mean about water potential?

Answer 1

Say you put salt in water. The water potential will decrease (become negative) because since there's an increase in solute concentration waters potential to move from high->low is somewhat lower due to its' properties. If you put water under pressure, you are increasing it's potential to move.

Answer 2

Does it mean the water's potential energy? Because the sugar molecules can't diffuse through the membrane, the water has to go to the sugar, thus, lowering the concentration of the sugar? If we think of side A as inside of the cell and side B as the oustide of the cell, it's like a hypertonic solution - there is more sugar on side B so the water will rush out of the cell and make the cell shrivel up.

Answer 3

So water potential in layman's terms? if you can

Answer 4

Add solute: water potential decrease
Add pressure or some form of energy: water potential increase
===bioboumani===

Answer 5

what would be an example of pressure or energy that could be added?
and why does it decrease when you add solute?