B2.1 - Diffusion

Question 1

Where does diffusion happen?

Answer 1

Diffusion happens in both solutions and gases because the particles in these substances are free to move about randomly.

Question 2

What is the rate of diffusion affected by?

Answer 2

The rate of diffusion is affected by the difference in concentration of the particles - the bigger the difference in concentration, the faster the diffusion rate.

Question 3

What can move in an out of cells by diffusion?

Answer 3

Dissolved substances.

Question 4

What sort of molecules can diffuse through cell membranes?

Answer 4

Only very small molecules can diffuse through cell membranes - things such as oxygen, glucose, amino acids and water. Big molecules like starch and proteins can’t fit through the membrane.

Question 5

What is diffusion?

Answer 5

Diffusion is the spreading out of particles from an area of high concentration (lots of particles) to an area of low concentration (fewer particles).