Osmosis & Plant Transport Flashcards
Concentration gradient
3 marks
Difference in concentration between;
- 2 solutions
- different cells
- or cells + a surrounding solution.
Flaccid
1 mark
Lacking turgor.
Lacking in stiffness or strength. Soft + floppy.
Humidity
2 marks
Amount of water vapour in the atmosphere measured as a percentage.
Potometer
1 mark
Device used to measure the rate of water uptake by a plant.
Selectively Permeable
1 mark
Property of a membrane that controls the movement of molecules depending on their size.
Transpiration
2 marks
Loss of water from leaves by evaporation through the stomata.
Turgid
1 mark
Having turgor; enlarged and swollen with water.
Visking tubing
2 marks
An artificial, partially-permeable membrane used in osmosis + diffusion experiments.
(Selectively/) Semi-permeable membrane
2 marks
- Allows some small substances to pass through
- Prevents larger substances.
Cell wall permeability
2 marks
Fully permeable - does not control what enters + leaves cell.
Cell membrane structure
2 marks
Rigid - provides a plant cell with support + keeps non-woody plants upright.
Osmosis in Cells depends on
1 mark
Concentration of water surrounding it.
Animal cells - osmosis
2 marks
When water moves into an animal cell - cell membrane stretches + cell gets bigger.
Example of an Animal Cell
1 mark
Red blood cell
Lysis
1 mark
Cell membrane bursts due to excess water intake.
Membrane stretches - gets bigger, then bursts due to excess water intake
(1 mark)
Lysis
Turgidity in plant cells
5 marks
Water diffusing into a plant cell = vacuole gets bigger, pushing cell membrane against the cell wall.
Force of this increases turgor pressure within cell making it firm or turgid.
When vacuole expands cell membrane is pushed against cell wall - pressure created by cell wall during osmosis in the Cells…does what?
(2 marks)
Stops too much water entering + prevents cell lysis.
If plants do not receive enough water
2 marks
Cells cannot remain turgid + plant wilts.
Cells that are not turgid
1 mark
Are flaccid.
Plasmolysis
1 mark
When too much water moves out of a plant cell + cell contents shrink - pulling the cell membrane away from the cell wall.
Cell state unlikely to survive
1 mark
Plasmolysed cell