Osmosis and Water Potential.
- Water Potential is the measure of the likelihood of water molecules to move from one place to another. The water molecules move at random and some will hit the surrounding membrane, creating a pressure known as the Water Potential.
- Water Potential is measured in units of pressure, usually kilo-pascals (kPa) or mega-pascals (MPa).
- The more water molecules that are able to move about freely, the greater the water potential.
- The greatest amount of water molecules possible are found in distilled water because only pure water is present - it therefore has the highest water potential and has a value of 0. Other solutions will have a negative water potential.
- In plants, you can use an equation to calculate the water potential:
Water Potential = Solute Potential + Pressure Potential.
- There are two factors that affect water potential; amount of solute and external pressure. If there is an increase in…