movement of substances through cells Flashcards

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1
Q

What does a high concentration gradient mean

A

The difference between the concentrations of both areas is very large

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2
Q

What is diffusion?

A

The net movement of particles from an area of high concentration to an area of low concentration due to their kinetic energy across a concentration gradient

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3
Q

What are four factors that can affect diffusion

A

Temperature
Distance
Concentration gradient
Surface area to volume ratio

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4
Q

Describe how temperature affects the rate of diffusion

A

The higher the temperature the more kinetic energy
So more collisions
So faster the rate of diffusion

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5
Q

Will diffusion be quicker with a high concentration gradient or a low concentration gradient?

A

High concentration gradient

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6
Q

Will rate of diffusion be faster in high surface area to volume ratio or low surface area to volume ratio
And explain why

A

High surface area to volume ratio (eg 6:1)

Because there will be more space for diffusion to occur across less space relative to its size

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7
Q

Explain why humans are made of many cells rather than one

A

Entire Human body has low surface area to volume ratio
so diffusion would happen slowly
and oxygen would not be able to be supplied to the body fast enough
So single cells provide high surface area to volume ratios so diffusion happens quickly

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8
Q

What restricts the free movement of particles to move outside a cell

A

The partially permeable cell membrane

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9
Q

Explain three ways in which diffusion helps living organisms

A
  • helps obtain nutrients (——
  • helps in gas exchange for respiration—–) (——
  • helps get rid of waste products——)
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10
Q

Which molecule for respiration moves through a leaf and where does enter from and where are they transported to?

A

Oxygen enters through the stomata and is transported to the mitochondria

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11
Q

Does diffusion require energy

A

No

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12
Q

Name two molecules that can not pass through the semi permeable membrane
and two that can

A

Starch and proteins CANT

glucose and amino acids CAN

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13
Q

Give an example of a cell adapted to diffusion and how it is adapted

A

The villi of the small intestine

It is folded so has an increased surface area to volume ratio

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14
Q

What is Osmosis

A

The diffusion of particles from a dilute solution to a concentrated solution across a semi permeable membrane

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15
Q

What is the water potential of a dilute solution

A

High water potential

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16
Q

What is the name given to two solutions with the same osmotic pressure

A

Isotonic solution

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17
Q

If a plant cell is placed in dilute solution, describe the movement of water and the name given to what happens to the cell

A

Water will move into the cell
Because water moves from dilute solutions(High water potential to concentrated solutions (low water potential )
cell becomes TURGID

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18
Q

If an animal cell is placed in dilute water, explain the movement of water and the name given to what happens to it

A

Water moves into the cell
Because water moves from dilute solutions(High water potential to concentrated solutions (low water potential )
This process is called LYSIS

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19
Q

If an animal cell is placed in concentrated solution of water, explain the movement of water and the name given to what happens to it

A

Water will move out
Because water moves from a more dilute solution(High water potential)to a more concentrated solution (low water potential)
Cell becomes CRENATED

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20
Q

If a plant cell is placed in concentrated solution of water, explain the movement of water and the name given to what happens to it

A

Water will move out of the cell
Because water moves from a more dilute solution(High water potential)to a more concentrated solution (low water potential)
The cell becomes FLACID

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21
Q

What is the name given to a plant cell that has lost toon,ugh water through osmosis

A

It become PLASMOLYSED

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22
Q

What is the name given to an animal cell placed in a dilute solution

A

Lysis

23
Q

Why are red onions good to use for osmosis

A

They are pigmented so you can easily see the direction of water movement

24
Q

Why does diffusion happen in terms of particles

A

Because of the kinetic energy of the particles

25
Q

Which potato cylinder will have the greatest mass?
One placed in salty solution?
Or dilute solution?

A

Dilute solution

26
Q

Is the concentration of carbon dioxide higher in the human cell or outside the human cell

A

Inside

27
Q

When the smallest of the agar cubes is placed in hydrochloride acid, what happens to it

A

Water travels inside the agar because diffusion happens from an area of high concentration to an area of low concentration
It becomes colorless the fastest

28
Q

What happens to the cytoplasm and membrane when a plant cell is placed in an extremely concentrated solution

A

They split apart and gaps appear

The cell is plasmolysed

29
Q

Why is there less water movement in animal cells

A

Because they have no cell wall so cannot resist changes in pressure

30
Q

What happens to the vacuole when water moves into a plant

A

It pushes against the cell membrane

31
Q

Which organelle is high turgor pressure caused by

A

The cytoplasm pushing against the cell membrane

32
Q

What state is a plant in when it is in Turgor

A

It is turgid

33
Q

Can diffusion happen in solids

A

No

Because diffusion requires the movement of particles

34
Q

Does diffusion need a membrane

A

No, can occur in the air for example

35
Q

Does osmosis require a membrane

A

Yes

36
Q

What is the definition active transport

A

The movement of particles form an area of low concentration to an area of high concentration agaisnt a concentration gradient by using the energy from respiration in the form ATP

37
Q

Does active transport transport require energy, and why

A

Yes

Because particles are moving against a concentration gradient

38
Q

Give an example of where active transport takes place in the body and why

A

From the lumen of the small intestine to the blood stream

as the cells in the blood stream are more concentrated

39
Q

Which organelle does the energy come from for active transport

A

The mitochondria

40
Q

Give an example of active transport in a plant and why it happens

A

When minerals are transported from the soil to the root hair cell because the content of the soil are much less concentrated than the cytoplasm of the root hair cell

41
Q

Why is active transport of glucose important in the kidney

A

So that glucose can be reabsorbed into the blood and not lost in urine

42
Q

Why should you convert original change in mass to percentage change in mass in an experiment to show effect of surface area on osmosis

A

Because you have different masses so percentage mass will give a more valid comparison

43
Q

Explain the effect of the different SA:Vol ratios on the mass of a potato in dilute solution
(2)

A

The larger the surface ares to volume ratio, the greater the percentage increase of mass
So The faster the rate of osmosis

44
Q

Cube of side- 0.5

What is the surface area of the cube

A

0.5 x 05
=0.25
0.25x6=
1.5

45
Q

Two leaves are covered in petroleum jelly
(LeafA)One is covered from only the upper half
(LeafB )The other one is covered only from the lower half
Which one decreases the most mass and why?

A

Leaf A as more water is lost as more surface area is exposed

46
Q

Beth draws the outiline of a leaf to investiagte the surface area.
It covers approximately 60 squares on squared paper
What is the total surface area of the leaf?

A

60 x 2= 120

Because total means both sides of the leaf

47
Q

Explain how nitrate ions get into the root hair cells of a plant

A

Through the process of active tranpsort,
when ions move from area of low concentration(in soil) to an area of high concentration(in the root hair cell)
against a concentration gradient,
using energy in the form ATP from respiration

48
Q

A doctor uses a dialysis machine to remove urea from the blood. But the machine also maintains normal blood glucose concentration.
Suggest now the concencentration of glucose in the solution around the tubing of the machine can help maintian normal glucose level in the blood.

A

Keep the concentration of glucose in the machine the same as the concentration in the machine.
So no net movement out of blood

49
Q

What is meant by thr independant variable

A

Thr variable thst you are changing

50
Q

If i increase the temperature of a solution containing seedlings that uses active transport to transport water into its cells, what will happen to the uptake of solution in the seedling

A

The rate of uptake will increase,

because higher temperatures makes the ions in the soltuion move faster

51
Q

A pot of seedlings contains a soltuion around them which uses active transport to transport water into the cell of the seedlings.
If i increase the concentration of the solution , what happens to the uptake of solution into the cell

A

Nothing

Because increasing concentration gradient does not have an effect on active transport

52
Q

How do root hair cells obtain water from the soil

A

Through the process of osmosis in the root hair cells

, because water travels from a more dilute solution to a less dilute solution across a semi permeable membrane

53
Q

Adding too much water into air spaces of soil prevents mineral ions from being absorbed.
Explain why

A

There is no oxygen
So cells cannot respire and thus release ATP
so active transport can not take place without ATP