Karteikarten
Diffusion and osmosis
Karten in diesem Stapel (24)
- 1A selectively permeable membraneAllows some but not all substances to pass through
- 2A semi-permeable artificial membrane used in the labVisking tubing
- 3The use of energy to move molecules against a concentration gradientActive transport
- 4DiffusionThe spreading out of molecules from a region of high concentration to a region of low concentration.
This is due to the kinetic energy of molecules and is therefore passive (does not require external energy). Diffusion is said to take place across a concentration gradient. - 5Adaptations of the alveoli to improve gas exchangeLarge surface area (numerous alveoli)
Thin walls
Moist - 6SolventA liquid that dissolves other substances e.g. water
- 7SoluteA substance that is dissolved e.g. salt or sugar dissolved in water
- 8SolutionMixture of solvent and solute e.g. salty water
- 9OsmosisThe diffusion of water molecules across a semi-permeable membrane from a region of high water concentration to a region of low water concentration.
(Also passive) - 10Hypertonic solutionLower concentration of water than the other solution
- 11Hypotonic solutionHigher concentration of water than the other solution
- 12Isotonic solutionEqual concentration of water to the other solution
- 13Animal cells in an isotonic solutionRemain the same, water moves in and out at the same rate.
- 14Animal cells in a hypotonic solutionGain water due to osmosis (Amoeba have contractile vacuoles to prevent bursting)
- 15Animal cells in a hypertonic solutionLose water due to osmosis, cells shrivels and dies (crenation)
- 16Examples of osmosisAbsorption of water by the plant roots
Re-absorption of water by the proximal and distal convoluted tubules of the kidneys
The turgor of plant cells gives support to non-woody cells
Opening and closing of stomata
Absorption of water by the stomach, small intestine, and colon.
Flow of water in the amoeba - 17Plant cells in an isotonic solutionRemain the same
- 18Plant cells in a hypotonic solutionGain water due to osmosis, becomes turgid
- 19Turgor / turgor pressureThe pressure of the cytoplasm and the vacuole against the cell wall of a plant.
- 20Plant cells in a hypertonic solutionLose water due to osmosis, the vacuole shrivel and move away from the cell wall. Becomes flaccid (limp) and wilts. The cell is then said to be plasmolysed.
- 21The reversal of plasmolysisDeplasmolysis --> put the cells in a hypotonic solution
- 22Cell wall of bacteriaPolysacccharides / protein
- 23Cell walls of fungiChitin
- 24Food preservation by osmosisSalting bacon/fish or preserving fruit and jam by adding sugar (hypertonic solution --> cell loses water --> enzymes no longer work --> cell dies)
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- Leaving Certificate Biology (Diffusion and osmosis) Karteikarten am Diffusion and osmosis, erstellt von eimearkelly3 am 10/07/2013.
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- eimearkelly3
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