osmosis Flashcards
What is osmosis
The passage of water from a region where it has a higher water potential to a region where it has lower water potential through a selectively permeable membrane
What is a solute
A solute is any substances that is dissolved in a solvent, for example water. The solute and the solvent together form a solution.
What is the symbol of water potential
Greek letter psi looks like a trident
Pure water is said to have a water potential of zero what does it follow
The addition of a solute to pure water will lower its water potential
the water potential of a solution must always be less than zero that is a negative value
The more solute added the lower the water potential
Water will move from a region of high to low water potential
How does osmosis actually work
A solution on the left has a low concentration of solute molecules while the solution on the right has a high concentration of solute molecules
Both the solute and water molecules are in random due to their kinetic energy
The selectively permeable plasma membrane, However, only allows water molecules across it and not solute molecules
The water molecules diffuse from the left hand side which has the higher water potential to the right hand side which has lower water potential, that is, down a water potential gradient
At the point where the water potentials on either side of the plasma membrane are equal, a dynamic equilibrium is established and there is no net movement of water
What is water potential
The highest value of water potential, that of pure water, is zero, and so all the other values are negative. The more negative the value, the lower the water potential
