Osmosis Flashcards
What is osmosis?
when water moves from a dilute solution to a concentrated solution through a partially permeable membrane.
Define dilute
A substance with a high concentration of the solvent, but a low concentration of the solute.
Define concentrated
A substance with a low concentration of solvent and a high concentration of solute.
What is an isotonic solution?
when concentration of solutes in solution outside cell = internal concentration of cell.
What is a hypertonic solution? How does this affect the cell?
when concentration of solutes in solution outside cell > internal concentration of cell.
Cell will shrivel due to movement of water out the cell & cytoplasm will become too concentrated.
What is a hypotonic solution? How does this affect the cell?
when concentration of solutes in solution outside cell < internal concentration of cell.
water will move into the cell via osmosis making the cell swell. Eventually, will burst as cytoplasm too dilute.
What is turgor pressure? What effect does this have on plants?
when the vacuole swells and presses up against the cell wall, creating so much pressure that no more water can enter the cell.
This makes the cells hard and rigid, creating firm leaves & stems.
What is the optimal condition for plant cells?
Hypotonic ─ keeps the cells turgid.
What happens to plant cells is hypertonic to surrounding solution?
Water will leave cells via osmosis ─ become flaccid, so plant wilts as the cells are soft.
If more water leaves, vacuole and cytoplasm shrink.
Cell membrane pulls away from cell wall ─ plasmolysis.
How do you investigate osmosis in plants cells?
1) putting plant tissue into different concentrations of salt/sugar solution & observing change of tissue.
2) measuring change in mass (don’t include liquid left outside plant tissue).
