Flashcards in Osmosis Deck (13):
What is osmosis?
-Diffusion of water across a selectively permeable membrane.
-It is a passive process and doesn't require energy.
What is a solute?
-Substance dissolved in a solvent forming a solution.
What is water potential?
-Pressure exerted by water molecules as they collide with a membrane.
What is the highest value for water potential?
-0, pure water has a water potential of 0.
Why is the highest value for water potential zero?
-Presence of a solute lowers the potential and zero is pure water.
What does more negative water potential mean?
What is the hydrostatic pressure?
-If solution is in a closed system and volume increases then there is an increase in hydrostatic pressure.
What happens if there is a higher water potential outside of an animal cell?
-Water moves into cell by osmosis.
-Increases hydrostatic pressure which results in membrane stretching and so cell swells and it bursts by an event called cytolysis.
What happens if there is a lower potential outside of an animal cell?
-Water moves out of the cell by osmosis.
-Reduction in cells volume and cell membrane puckers and shrinks which is referred to as crenation.
What happens if the animal cell and the outside has an equal water potential?
-Water constantly leaves and enters the cell so there is no change in the state of cell.
What happens if there is a higher water potential outside a plant cell?
-Water enters cell, increase in hydrostatic pressure which pushes the membrane against the cell wall.
-The cell swells and becomes turgid.
What happens if there is a lower water potential inside a plant cell?
-Water leaves plant cell, membrane pulled away from cell wall.
-The cell is plasmolysed.