Osmosis

Question 1

What is osmosis

Answer 1

The net movement of water molecules from a region of high water potential to a region of low water potential through a selectively permeable membrane

Question 2

What is the water potential of pure water

Answer 2

0

Question 3

What happens is solute is added to pure water

Answer 3

The water potential is lower and negative

Question 4

Describe an example of osmosis where a solution has a high concentration of glucose

Answer 4

• note glucose and water molecules are in random motion due to kinetic energy
• selectively permeable membrane only allows water molecules through
• water diffuse from a region of high water potential to a region of low water potential
• when water potential on either side of membrane are equal a Demi equilibrium has been reached

Question 5

The external solution has a lower water potential (animal)

Answer 5

• water leaves the cell

- the cell shrinks

Question 6

The external solution has higher water potential than inside the cell(animal)

Answer 6

• water enters the cell

- becomes lyse/burst

Question 7

Water potential of external solution is higher than inside plant cell

Answer 7

• water enters cell

- protoplast pushed against cell wall and becomes turgid

Question 8

The external water potential is the lower than inside the plant cell

Answer 8

• water leaves the cell

- protoplast pulled away from cell wall and becomes plasmolysed

Question 9

Incipient playmolysis

Answer 9

Cell membrane and cytoplasm are partially detached from the cell wall due to insufficient water to make cell turgid

Question 10

Isotonic solution

Answer 10

A solution in which the concentration of solutes is essentially equal that of the cell which resides in the solution