B3- Movement into and out of cells

Question 1

Define Diffusion

Answer 1

net movement of particles from a region of their higher concentration to a region of their lower concentration as a result of their random movement

Question 2

The steeper the concentration gradient…

Answer 2

the faster the rate of diffusion

Question 3

What factors does the rate of diffusion depend on? [4]

Answer 3

1. Surface area
2. Temperature
3. Concentration Gradient
4. Distance

Question 4

How + Why does surface area affect rate of diffusion? [2]

Answer 4

1. The larger the surface area to volume ratio, the faster the rate of diffusion
2. the shorter the distance to the middle, the larder the surface area : volume ratio

Question 5

How + Why does temperature affect the rate of diffusion? [2]

Answer 5

1. The higher the temperature, the higher the rate of diffusion
2. High temp= High kinetic energy- particles move quicker

Question 6

How + Why does concentration gradient affect the rate of diffusion?

Answer 6

1. Larger difference in concentration gradient=higher the rate of diffusion

Question 7

How + Why does distance affect the rate of diffusion? [2]

Answer 7

1. Shorter the distance=faster the diffusion
2. greater distance, more time for particles to travel

Question 8

Define Osmosis

Answer 8

the net movement of water molecules from a region of their higher water potential to a region of low water potential through a partially permeable membrane

Question 9

High water potential is the same thing as

Answer 9

low solute concentration

Question 10

Low water potential is the same thing as

Answer 10

high solute concentration

Question 11

Isotonic meaning

Answer 11

same water potential

Question 12

Hypertonic meaning

Answer 12

lower water potential

Question 13

Hypotonic meaning

Answer 13

higher water potential

Question 14

Define and explain Turgid

Answer 14

1. firm
2. water moves into the plant cell
3. organelles press against wall

Question 15

Define and explain Plasmolysis

Answer 15

1. Floppy
2. Water moves out of the plant cell
3. organelles are pulled away from cell wall

Question 16

Define and explain Haemolysis

Answer 16

1. Burst
2. Water moves into the RBC and bursts leaving just membrane behind

Question 17

Define and explain crenated

Answer 17

1. Shrunk
2. Water moves out of the RBC and shrinks making it crenated

Question 18

Define Active Transport

Answer 18

The movement of particles against a concentration gradient using energy released during respiration

Question 19

Three features of Active Transport

Answer 19

1. uses energy from respiration
2. particles move against a concentration gradient
3. using special protein carriers

Question 20

Importance of active transport in root hairs [3]

Answer 20

1. high concentration of minerals in root hair cells
2. need AT to transport more from soil
3. Water molecules enter the roots by osmosis because root hair cells have low water potential, they have high solute

Question 21

Importance of active transport in small intestine [2]

Answer 21

1. Glucose + other nutrients go from the small intestine to the blood against the concentration gradient
2. ensures all nutrients enter the blood