Worksheets and lesson ideas to challenge students aged 11 to 16 to think hard about active transport, osmosis and diffusion (GCSE and Key Stage 3)
How do substances such as glucose, carbon dioxide and water get into cells? Cell transport is a fantastic area of biology that links together lots of different concepts, requiring synoptic thinking e.g. active transport requires an understanding of respiration, protein structure and concentration gradients. Start by asking students what substances move into and out of cells and then think about the problems that the cell must overcome. The membrane is made of lipid but water and oil do not mix so how does osmosis take place? Glucose is a massive molecule so how can it diffuse across a membrane made from tightly packed hydrocarbon chains?
GCSE activity on active transport in waterlogged soil. Students think through the problem of why plants grown in waterlogged soil show nitrate deficiency. They apply their knowledge to figure out that water displaces oxygen from the soil. As such, aerobic respiration cannot take place, which means no ATP is available for active transport. This problem also links to the concepts of leaching and denitrification. This is a great thinking problem as it links together many important concepts in biology. This activity can be extended by asking students to come up with a way to determine which of the three factors that cause nitrate deficiency is most important. (PDF)
GCSE practical to investigate how the rate of diffusion is affected by temperature. Students measure the rate of diffusion of food dye at different temperatures. Students also apply their understanding of diffusion and temperature to gas exchange in cold-water worms. (PDF)
GCSE activity looking at how osmosis affects freshwater and marine organisms. Students work in small groups to apply their understanding of osmosis to explain different adaptations in marine and freshwater organisms. This activity requires students to have a good understanding of the principles of osmosis so they can apply their knowledge to new situations. (PDF)