B2.1.1 Diffusion

Question 1

Define diffusion

Answer 1

Diffusion is the passive net movement of particles from a region of high concentration to low, down a concentration gradient

Question 2

Explain how oxygen diffuses from the air in your lungs into
your blood

Answer 2

Oxygen moves across the thin walls of the alveoli into the surrounding capillaries due to a concentration gradient
Hameoglobin in red blood cells binds to oxygen, facilitating its transport throughout the body in blood

Question 3

Factors affecting the rate of diffusion

Answer 3

Distance
Concentration gradient
Surface area

Question 4

To increase rate or diffusion (3)

Answer 4

Decrease distance particles need to move, takes less time to travel a shorter distance
Increase concentration gradient. The steeper the CG the greater the net movement of particles
Increase surface area, allows more space for diffusion so more particles can move in a period of time

Question 5

What is a concentration gradient

Answer 5

When one region has a higher concentration of particles than another