Topic Nine (1.9): Movement of substances

Topics Icon.png Objectives

By the end of this topic you should be able to:

  • name some substances that move into and out of cells;
  • describe the process of diffusion.

Introduction Icon.png Introduction

In this topic, you will find out how lots of substances move in and out of cells.


Interact Icon.png Working through your coursebook

  • Read pages 20–21 in Activate 1.
  • Diffusion is the movement of particles from a high concentration to a low concentration. It is responsible for the movement of oxygen into the blood from the alveoli in the lungs, for carbon dioxide leaving respiring cells and plants wilting.
  • Pay attention to the diagrams on page 21.

WATCH - B1 1.4 Animation: Diffusion in cells (Kerboodle) Links to an external site.


Review Icon.png Review

COMPLETE - B1 1.4 Interactive screen: Factors affecting diffusion (Kerboodle) Links to an external site. 

COMPLETE - B1 1.4 Interactive screen: Diffusion - true or false? (Kerboodle) Links to an external site.


Bridge Icon.png Support activity for this topic

WATCH - Diffusion | Revision Monkey (YouTube)


Stretch Icon.png Extension activity for this topic

EXPLORE - Agar cube diffusion (Twig) - [Not available on sample course]