Osmosis

what is water potential?

the tendency of water to move out of a solution

what is the water potential of a dilute solution?

dilute solution = high water potential

what is the water potential of concentration solution?

concentrated solution = low water potential

what is the meaning of osmosis?

the net movement of water molecules from a higher water potential to a region of lower water potential, through a partially permeable membrane

what happens to the water potential when more solutes are dissolved in a solution?

the more negative the water potential, the lower the water potential value

what is the water potential of pure water?

0kPa

what happens when osmosis is into a water cell?

• plant cell is place into a dilute solution

• water enters the cell’s cytoplasm and vacuole by osmosis

• volume of cell increases

what do the protoplasts in a plant cell do when there is osmosis into the plant cell?

they push against the cell wall, increasing pressure and the cell becomes more turgid

how does turgidity help the plant?

it provides the plant with strength and support

what happens when there is osmosis out of the plant?

• plant cell is placed into a concentrated solution

• water leaves the cell’s cytoplasm and vacuole

• the cell’s volume decreases

what happens to the plant’s protoplasts when osmosis is out of the cell?

they shrink and pull away from the cell wall, decreasing the pressure

what eventually happens to a plant’s protoplasts cell if water leaves it?

it becomes plasmolysed

what is a hypotonic solution?

solution outside the cell is less concentrated/more diluted than inside the cell

what is a hypertonic solution?

the solution outside the cell is more concentrated than inside the cell

what is a isotonic solution

the solution outside and inside the cell are similar in concentration