Transport in cells

Question 1

What is the concentration gradient

Answer 1

Difference in concentration between 2 areas

Question 2

What is the correlation between concentration gradient and diffusion rate

Answer 2

The higher the concentration gradient the faster the rate of diffusion

Question 3

Give 4 examples of diffusion

Answer 3

1) Oxygen and glucose into body cells from bloodstream (respiration)
2) CO2 into actively photosynthesising plant
3) Gas exchange in lungs
4) Simple sugars and amino acids from gut to cell membranes

Question 4

There is a shallow concentration gradient between either side of the cell membrane.

If 3 particles move to the right side of the membrane but 7 move to the left then what is the net movement

Answer 4

The net movement is 4 particles to the left

Question 5

In osmosis, there is a net movement of particles from a ______ solution (high water concentration), to a more _________ solution (low water concentration)

Answer 5

.Dilute

.Concentrated

Question 6

What is the term for 2 solutions that have the same concentration

Answer 6

Isotonic

Question 7

The term for a more concentrated solution (more solute less water) is _______

Answer 7

HypERtonic

—-

Question 8

The term for a more dilute solution (more water less solution) is _______

Answer 8

HypOtonic

—

Question 9

What happens to an animal cell if the solution around it is:
A) hypotonic
B) hypertonic

Answer 9

A) Water will move into the cell via osmosis (cell swells and could burst)
B) Water moves out of the cell via osmosis (cell shrinks)

Question 10

What is turgor pressure

Answer 10

When no more water can enter a cell because of pressure inside

Question 11

What happens to cause turgor pressure

Answer 11

1) Water into plant cell
2) Vacuole swells
3) Cytoplasm pressed against cell wall
4) Cell rigid and so do leaves + stem

Question 12

What happens to plant cells in a hypertonic solution

Answer 12

They lose water, become flaccid and wilts

Question 13

What is plasmolysis

Clue: opposite of turgor pressure process

Answer 13

1) Plant cell placed in hypertonic solution
2) Water leaves cell
3) Vacuole + cytoplasm shrink
4) Membrane pulls away from cell wall

Question 14

Why can plant tissue be used as an osmometer

Answer 14

It reacts very strongly to concentration of external solution

Question 15

Why does active transport require energy from respiration

Answer 15

It acts against the concentration gradient

Question 16

Give an example of active transport in plant roots

Answer 16

Root hair cells absorb mineral ions from dilute solutions in the soil

Question 17

Give an example of active transport in the digestive system

Answer 17

Glucose can be absorbed from gut/(kidney tubules) against large concentration gradient

Question 18

Give an example of active transport failure in people with cystic fibrosis

Answer 18

They have thick and sticky mucus in active transport system as mucus not working properly in mucus cells

Question 19

What is the correlation between the surface are to volume ratio and the size of an organism

Answer 19

Surface area to volume ratio decreases as size increases

Question 20

Why can single celled organisms perform all necessary exchanges with environment on their surface

Answer 20

They have a relatively large surface area to volume ratio

Question 21

Why do larger organisms have efficient exchange surfaces

Answer 21

Because they have many cells that can’t make contact with the environment

Question 22

Give the properties that an efficient exchange surface must have at least one of

Answer 22

1) large surface area
2) Thin membranes
3) Short diffusion path
4)

Question 23

Give the properties that an efficient exchange surface must have

Answer 23

1) large surface area
2) Thin membranes
3) Short diffusion path
4) Efficient transport system

Question 24

Give a way in which a gaseous exchange surface in an animal is ventilated

Answer 24

Oxygen absorbed by alveoli in lungs during breathing

Question 25

Purpose of villi in small intestine and adaptations

Answer 25

1) Absorb soluble food molecules
2)
- Large surface area
- Short diffusion path
- Good blood supply

Question 26

How are leaves modified for efficient gas exchange

Answer 26

Leaves are flat with internal air spaces and stomata to allow gases in/out of leaves