1 Cell Biology - Cell Transport Flashcards Preview

AQA Biology Paper 1 11-1A > 1 Cell Biology - Cell Transport > Flashcards

Flashcards in 1 Cell Biology - Cell Transport Deck (37)
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1

Define 'diffusion'.

Net movement of particles from an area of high to low concentration (down concentration gradient)

2

What does it mean by 'net movement'?

Overall movement: particles can move in any direction, but generally speaking, most of the particles are moving in one particular direction, hence 'net' movement

3

State three factors that affect the rate of diffusion.

Concentration gradient, temperature, surface area

4

How does concentration difference affect the rate of diffusion?

Higher conc difference/Steeper conc gradient --> faster diffusion

5

Explain why a higher temperature results in faster diffusion.

More kinetic energy, particles move around more

6

Name a substance that diffuses into our cells for use.

Oxygen, glucose

7

Name a substance that diffuses out of our cells to be removed.

Carbon dioxide, urea

8

Name a structure in the body that is adapted to increase diffusion rate.

Alveoli, villi

9

Define 'osmosis'.

Net movement of water molecules down the water concentration gradient through a partially permeable membrane

10

Define 'dilute'.

A solution with a high water conc, but low solute conc

11

Define 'concentrated'.

A solution with a low water conc, but high solute conc

12

What are partially permeable membranes?

Membranes that only allow some types of substances to pass through

13

What is an isotonic solution?

A solution with the same solute conc as the cell

14

What is a hypertonic solution?

A solution with a higher solute conc than the cell

15

What is a hypotonic solution?

A solution with a lower solute conc than the cell

16

If a cell is in a hypertonic solution, water will ___ (enter/leave) the cell.

Leave

17

If a cell is in a hypotonic solution, water will ___ (enter/leave) the cell.

Enter

18

What will happen to an animal cell if it is in a hypertonic solution?

Water leaves cell --> shrivelled

19

What will happen to an animal cell if it is in a hypotonic solution?

Water enters cell --> burst

20

Why do animal cells burst in hypotonic solutions?

No cell wall

21

What will happen to a plant cell if it is in a hypertonic solution?

Water leaves cell --> plasmolysed

22

What will happen to a plant cell if it is in an isotonic solution?

No net water movement --> flaccid

23

What will happen to a plant cell if it is in a hypotonic solution?

Water enters cell --> turgid

24

What does 'plasmolysed' mean?

The cell membrane becomes detached from cell wall

25

Why does the potato skin needs to be removed before putting the potato cylinders into the solutions?

Skin is impermeable

26

How do we calculate % change in mass?

(final mass - intial mass)/initial mass x 100

27

Define 'active transport'.

Movement of particles against the concentration gradient (low to high) using energy in the form of ATP

28

Explain the importance of active transport in plants.

Root hair cells carry out AT to absorb mineral ions effectively in dilute soil

29

Explain the importance of active transport in animals.

Cells in gut lining does AT to absorb glucose effectively from the bloodstream

30

State one adaptations cells may have if they need to carry out active transport.

Lots of mitochondria for respiration for energy