1 Cell Biology - Cell Transport Flashcards

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1
Q

Define ‘diffusion’.

A

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

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2
Q

What does it mean by ‘net movement’?

A

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

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3
Q

State three factors that affect the rate of diffusion.

A

Concentration gradient, temperature, surface area

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4
Q

How does concentration difference affect the rate of diffusion?

A

Higher conc difference/Steeper conc gradient –> faster diffusion

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5
Q

Explain why a higher temperature results in faster diffusion.

A

More kinetic energy, particles move around more

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6
Q

Name a substance that diffuses into our cells for use.

A

Oxygen, glucose

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7
Q

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

A

Carbon dioxide, urea

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8
Q

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

A

Alveoli, villi

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9
Q

Define ‘osmosis’.

A

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

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10
Q

Define ‘dilute’.

A

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

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11
Q

Define ‘concentrated’.

A

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

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12
Q

What are partially permeable membranes?

A

Membranes that only allow some types of substances to pass through

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13
Q

What is an isotonic solution?

A

A solution with the same solute conc as the cell

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14
Q

What is a hypertonic solution?

A

A solution with a higher solute conc than the cell

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15
Q

What is a hypotonic solution?

A

A solution with a lower solute conc than the cell

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16
Q

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

A

Leave

17
Q

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

A

Enter

18
Q

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

A

Water leaves cell –> shrivelled

19
Q

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

A

Water enters cell –> burst

20
Q

Why do animal cells burst in hypotonic solutions?

A

No cell wall

21
Q

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

A

Water leaves cell –> plasmolysed

22
Q

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

A

No net water movement –> flaccid

23
Q

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

A

Water enters cell –> turgid

24
Q

What does ‘plasmolysed’ mean?

A

The cell membrane becomes detached from cell wall

25
Q

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

A

Skin is impermeable

26
Q

How do we calculate % change in mass?

A

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

27
Q

Define ‘active transport’.

A

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

28
Q

Explain the importance of active transport in plants.

A

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

29
Q

Explain the importance of active transport in animals.

A

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

30
Q

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

A

Lots of mitochondria for respiration for energy

31
Q

How does active transport differ from diffusion and osmosis?

A

AT uses energy, D and O do not

32
Q

State two differences beween diffusion and osmosis.

A

D: Any particles, does not need a membrane; O: Water specific, needs partially permeable membrane

33
Q

State the relationship between size and surface area to volume ratio.

A

The bigger the size, the smaller the SA:V

34
Q

Describe three adaptations of exchange surfaces.

A

Large SA, thin membrane/surface, ability to maintain high conc difference

35
Q

How are alveoli adapted for efficient gaseous exchange?

A

Large SA, thin membrane (short diffusion distance), rich blood supply (maintain steep conc gradient)

36
Q

How are plant roots adapted for efficient water and mineral absoprtion?

A

Large SA (root hairs), transpiration stream

37
Q

How does stomata help maintain efficient gas exchange in leaves?

A

Allow gases to move in and out of leaf, maintaining steep concentration gradient