B2.1.2 Osmosis Flashcards
Define osmosis
The movement of water molecules from a high water potential to a lower water potential through a partially permeable membrane
What is water potential
Concentration of free water molecules
The…..greater the rate of osmosis
Greater the difference in water potential, the
What happens to a plant cell when surroundings are a less concentrated solution than cell contents
Takes up water by osmosis
Turgor pressure in cell increases
Cell becomes turgid
What happens to plant cells when surroundings have same concentration as cell contents
No net movement of water.
Cell remains the dame
What happens to plant cell when surroundings are a more concentrated solution than cell contents
Loses water by osmosis
Turgor pressure falls
Cell becomes flaccid
Eventually, cell contents collapse away from cell wall
That’s called a plasmolysed cell
What happens to animal cell when surroundings are a less concentrated solution than cell contents
Takes up water
Swells and may burst
Lysis
What happens to animal cell when surroundings have same concentration as cell contents
No net movement of water
Cell remains the same
What happens to animal cell when surroundings are a more concentrated solution than cell contents
Loses water by osmosis
Cell becomes crenated
