1.4 - Diffusion

Question 1

What is diffusion?

Answer 1

The spreading out of particles of:

• a gas
• any substance in a solution

Question 2

What does the net particle movement in and out of cells depend on?

Answer 2

The concentration of particles on each side of the cell membrane

Question 3

Describe the net movement of particles

Answer 3

There will be a net movement from an area of high concentration to low concentration

Question 4

What is a concentration gradient?

Answer 4

The difference in concentration between two areas

Question 5

How does the concentration gradient affect the rate of diffusion?

Answer 5

The larger the concentration gradient, the faster the rate of diffusion

Question 6

Give three examples of diffusion

Answer 6

1) The diffusion of oxygen into cells of the body from the bloodstream as the cells are respiring
2) The diffusion of carbon dioxide into actively photosynthesising plant cells
3) The diffusion of simple sugars and amino acids from the gut through cell membranes