4.3 Osmosis Flashcards
What is the definition of osmosis?
The net movement of water from a region of higher water potential to a region of lower water potential through a partially permeable membrane.
Definition of pure water
Water with a water potential of 0
Osmosis in terms of water potential
Water moves from a less negative region to a more negative region because the more concentrated a solution is the more negative it will be ( lower WP)
Explain what happens when the water potential of an external solution is higher than the cell contents solution in a plant cell
The water enters the cell causing the protoplast to swell and push against the cell wall. Resulting in the cell going turgid.
Explain what happens when the water potential of an external solution is lower than the cell contents solution in a plant cell
The water moves out the cell causing the protoplast to shrink and be pulled away from the cell wall, resulting in the cell shrinking ( plasmolysed)
What are the three main parts of a plant cell in osmosis?
~ the vacuole- consisting of sugar and salt solution, In cell
~the protoplast-consisting of the outer surface membrane, the nucleus, cytoplasm and inner membrane
The cell wall - a tough inelastic organelle, which remains the strength of the cell
Explain what happens when the water potential of an external solution is higher than the cell contents solution in a animal cell
The water enters the cell causing the cell to swell and burst (lysis)
Explain what happens when the water potential of an external solution is lower than the cell contents solution in a animal cell
The water leaves the cell and the cell shrinks, causing it to remain flaccid
How does a solution form
A solute and solvent from a solution
The solute is the solid that dissolves.
The solvent is the liquid in which the solute dissolves in
