D2.3 Water potential Flashcards
Solvent
Liquids that dissolve solutes to form solution.
Solvent
Substances dissolved in solutions.
Solvation
The process of dissolving a solute into a solvent.
Hypertonic
Higher solute concentration
Hypotonic
Lower solute concentration
Isotonic
The same solute concentration
Explain the net movement of water up the concentration gradient:
- Water is attracted to solutes in a solution, water moves from hypotonic solution to hypertonic solution.
Water potential
Measure of the potential energy per unit volume in pascal/kilopascal.
How do animal cells (hypertonic) minimize the amount of water they take in?
- They use contractile vacuoles to excrete water.
- Extracellular fluids must be kept isotonic; kidneys in humans are used to regulate the solute concentration of extracellular fluids.
How do plant cells respond to a a hypotonic solution?
Increased volume of the cytoplasm increases turgid pressure as it pushes against the cell wall.
How are isotonic solutions used in medicine/
- Isotonic solution is used for IV drip so that human cells do not gain or lose water.
- tissues/organs used medical procedures is bathed in isotonic solution to prevent osmotic damage.
What is the water potential of water at STP (20 celsius)?
0
What is the net movement of water?
It moves from high water potential to low water potential because this minimizes its potential energy.
How does plant tissue act in hypotonic solution?
Water moves from the solution to the tissue, opposite if the plant is fullt turgid.
When plant tissue is bathed in hypertonic solution…
Solute concentration is more negative in the solution as it is higher, and water moves from tissue to the solution.
Plasmolysis
When the plasma membrane is pulled away from the cell wall due to a loss of volume of cytoplasm in a plant cell.
Movement of water between cells with different water potentials…
From cell with high water potential to cell with low water potential.
