Introduction

This topic focuses on ways in which different molecules move in and out of cells. Learning the definitions and key points is essential for this topic.

To begin, learn the definition for diffusion and the role of kinetic energy in diffusion. You need to be able to describe and explain how diffusion is affected by surface area, temperature, concentration gradients and diffusion distances. Diagrams such as the one on page 18 (Figure B2.03) help illustrate the idea of concentration gradients and movement by diffusion. Try to remember labelled diagrams like this, as they are effective summaries of quite complex ideas.

Reading

Read and make notes on pages 17-19 of your coursebook.

Tasks

Make a labelled copy of the diagram on page 18 (Figure B2.03) and then attempt the in-text questions on page 19. Check your answers.

Add keywords and their meanings to the glossary file and or the Quizlet App.

Links

EXPLORE – Diffusion Definition (Twig) [Not available with sample course]

WATCH - What is Diffusion? How Does it Work? What Factors Affect it? (YouTube)