B4d-diffusion and osmosis Flashcards Preview

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Flashcards in B4d-diffusion and osmosis Deck (19)
1

What is diffusion?

The net movement of particles from an area of higher concentration to an area of lower concentration

2

What is diffusion a consequence of?

The random movement of individual particles

3

What do cell membranes do in diffusion?

-They let molecules in and out
-only small molecules can diffuse through

4

What is the rate of diffusion increased by?

Shorter distance
Greater concentration difference(gradient)
Greater surface area

5

How does a short distance affect the rate?

Substances diffuse quicker when they dont have to move as far

6

How does concentration gradient affect the rate?

-Substances diffuse faster if there is a bigger difference
-more on one side means more to move across

7

How does surface area affect the rate?

-More surface area means more room for molecules to move across
-faster they can get to one side

8

What is osmosis?

The net movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration

9

What does partially permeable mean?

A membrane with very small holes in it

10

What does the plant cell wall provide?

Support

11

How does turgor pressure help support the plant tissues?

Contents of cell push against the inelastic cell wall

12

Why does a plant wilt because of lack of water?

The cells start to lose water and so lose their turgor pressure

13

What is flaccid?

When a cell loses turgor pressure

14

What is plasmolysed?

When the cytoplasm inside the cell shrinks and the membrane pulls away from the cell wall due to lack of water

15

What is turgid?

Plump and swolllen

16

Where does water move in and out in animal cells?

Through the cell membrane

17

What is lysis?

When an animal cell takes in tok much water and it bursts

18

What is crenation?

When an animal cell loses too much water and it gets shrivelled up

19

Why are animal cells affected by changes in the amount of water?

They have no cell wall so they have to make sure the amount of water in their cells is constant