04 December 2020 The role of diffusion Learning
04 December 2020 The role of diffusion Learning objectives: To collect data and analyse it to explain the connection between surface area and rate of diffusion.
Starter (5 mins) • Prediction about how big the biggest cell in the world is? ? ?
• Nerve cell • 12 metres in length! However, despite their length they are still only around 0. 5 mm in width.
• Cells need water, oxygen and other substances in order to carry out processes such as respiration. • Some substances are able to travel through the cell membrane by a process called diffusion.
Animal cell
• Work in pairs. • Practicals and Investigations sheet ‘Jelly cells and diffusion’. • Read through the sheet and complete the risk assessment, then decide on the sizes they will use for the cubes and design a results table. • After going through some of their ideas, and checking they understand the method, allow the students to proceed with the investigation.
• Once they have gathered results, students should plot line graphs to display their results and write a conclusion using the information on the practical sheet.
• Diffusion is when particles move from one area to another. • They move from a high concentration to a low concentration.
Plenary (5 mins) • Explain why individual cells must stay small. • Use the words: diffusion, cell membrane and surface area in their answer.
- Slides: 9