Osmotic Pressure Flashcards
what is osmotic pressure
Osmotic pressure is the external pressure required to prevent the net movement of a solvent across a semipermeable membrane.
Describe the direction of osmosis.
Osmosis occurs from a region of high water potential (lower solute concentration) to a region of low water potential (higher solute concentration) to dilute the solute.
What happens to solvent molecules during osmosis?
Solvent molecules diffuse through a selectively permeable membrane towards the area of higher solute concentration.
What is an isotonic solution?
An isotonic solution has the same osmolality of dissolved solutes inside and outside the cell, resulting in no net movement of water.
What is a hypotonic solution?
A hypotonic solution has a lower osmolality outside the cell, causing water to move into the cell, leading to cell expansion and increased turgor pressure.
What occurs in a hypertonic solution?
In a hypertonic solution, the osmolality is greater outside the cell, leading to water moving out of the cell, causing cell shrinkage and loss of turgor pressure.
What is plasmolysis?
Plasmolysis occurs when a plant cell loses water in a hypertonic solution, leading to the disintegration of the cell membrane and a puckered appearance.
How does osmotic pressure affect limp celery placed in water?
The higher concentration of solutes in the celery creates a concentration gradient that draws water into the celery, increasing turgor pressure and restoring crispness.
