2.5 Osmosis Flashcards Preview

A Level Biology > 2.5 Osmosis > Flashcards

Flashcards in 2.5 Osmosis Deck (18):
1

What happens to red blood cells when the solution surrounding has a higher water potential?

Water enters cell
Cell swells and bursts

2

What happens to red blood cells if the cell and solution have equal water potentials?

Water constantly enters and leaves
Cell experiences no change

3

What happens if the solution has lower water potential than the red blood cell?

Water leaves cell
Cell shrinks

4

What happens to plant cells if the solution surrounding has a higher water potential?

•Water enters cell
•Protoplasts swell and become turgid (pushed against cell wall)

5

What happens to plant cells when the cell and solution have equal water potential?

Water constantly enters and leaves
No change in protoplasts (begin to pull away from cell wall)

6

What happens to plants cells if the external solution has a lower water potential?

Water leaves cell
Plasmolysis shrinks
Protoplasts pull away from cell wall

7

What is water potential?

A measure of the tendency of water to move freely

8

What is the water potential equation?

Water potential = solute potential + pressure potential

9

What is the highest water potential?

0

10

What are the units for water potential?

kPa

11

What effect does adding solutes have on water potential?

It lowers the value

12

The more solute added...

... The more negative the value

13

What effect does pressure potential have on water potential?

Pressure potential increases the tendency of water to move through a membrane

14

Is the solute potential value positive or negative?

Negative

15

Is pressure potential value positive or negative?

Positive

16

What is osmosis?

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

17

What is hydrostatic pressure?

When water diffuses into a closed system e.g. Cell causing increased volume and pressure

18

What is cytolysis?

Cell cannot withstand the increased pressure so it bursts

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