Diffusion And Osmosis Flashcards Preview

Biology module 4 > Diffusion And Osmosis > Flashcards

Flashcards in Diffusion And Osmosis Deck (19):
1

Describe diffusion

The movement of a substance from a region of high to low concentration

2

How does water move in and out of plant cells?

By osmosis through the cell membrane

3

What is the purpose of a plant cell wall?

To provide support

4

What can a lack of water cause plants to do?

Wilt

5

Where does water move in and out of animal cells?

Through the cell membrane

6

Describe how carbon dioxide and oxygen diffuse in and out if plants through the leaves

- The concentration of carbon dioxide outside the cell is greater than the concentration inside, so carbon dioxide diffuses into the cell
- The concentration of oxygen inside the cell is greater than the concentration inside, so oxygen diffuses out of the cell

7

Explain the net movement of particles by diffusion

From an area of high concentration to an area of low concentration, as a consequence of the random movement of individual particles.

8

Explain how the rate of diffusion is increased

- the particles have a shorter distance to travel
- the cell membrane's surface area is bigger
- there is a bigger difference between concentrations (a steeper concentration gradient)

9

How do substances move in and out cells by diffusion through the cell membrane?

By diffusion through the cell membrane

10

Describe osmosis

The movement of water across a partially-permeable membrane from an area of high water concentration to an area of low water concentration

11

What is osmosis?

A type of diffusion

12

Explain the term partially-permeable membrane

Membrane that allows only certain molecules or atoms through, graded by size

13

Explain how plants are supported by turgor pressure within cells

Water pressure activity ng against inelastic cell wall

14

Explain wilting in terms of a lack of turgor pressure

As the amount of water inside the cells reduces, the cells become less rigid due to reduced pressure

15

Describe the effects of the uptake and loss of water on animal cells

If too much water enters a cell it could burst
If too little water they shrivel up and become crenated

16

Explain the net movement of water molecules by osmosis

From an area of high water concentration to an area of low water concentration across a partially permeable membrane, as a consequence of the random movement of individual particles.

17

Explain the term flaccid

A plant cell that is limp through a reduction or pressure inside the cell

18

Explain the term plasmolysed

A plant cell that has lost water causing the cell membrane to be pulled away from the inside of the cell wall

19

Explain the term turgid

A plant cell fully inflated with water