Define what is Learning activities: Exampro: Movement of molecules by diffusion and students observe diffusion BYA1 Jan 2005 Q5 – and ions down weeks facilitated diffusion. using agar cubes containing concentration gradients BYA1 June 2004 Q6 Explain the process – phenolphthalein. Place in by simple diffusion or of facilitated Rich question: dilute NaOH solution for 5–10 facilitated diffusion. diffusion. minutes and cut the cubes Show students a list of Identify open to show where NaOH substances and ask substances rely on has diffused to. This could be them to categorise facilitated diffusion conducted with different those which can diffuse and why they concentrations to highlight by simple diffusion and cannot enter/leave diffusion gradients those that cannot. cells by diffusion. teacher explanation of factors Interpret data to which affect the rate of identify when a diffusion substance is teacher explanation of why moving by water-soluble molecules facilitated diffusion cannot pass across the or diffusion. phospholipid bilayer by diffusion. Introduce facilitated diffusion and the role of channel and carrier proteins. Use animations and video clips to support discuss some data showing data on facilitated diffusion and ask students to explain trends. an answer.
Movement of molecules and ions down concentration gradients by simple diffusion or facilitated diffusion. weeks Define what is by diffusion and facilitated diffusion. Explain the process of facilitated diffusion. Identify substances rely on facilitated diffusion and why they cannot enter/leave cells by diffusion. Interpret data to identify when a substance is moving by facilitated diffusion or diffusion. Learning activities: students observe diffusion using agar cubes containing phenolphthalein. Place in dilute NaOH solution for 5–10 minutes and cut the cubes open to show where NaOH has diffused to. This could be conducted with different concentrations to highlight diffusion gradients teacher explanation of factors which affect the rate of diffusion teacher explanation of why water-soluble molecules cannot pass across the phospholipid bilayer by diffusion. Introduce facilitated diffusion and the role of channel and carrier proteins. Use animations and video clips to support discuss some data showing data on facilitated diffusion and ask students to explain trends. an answer. Exampro: BYA1 – Jan 2005 Q5 BYA1 – June 2004 Q6 Rich question: Show students a list of substances and ask them to categorise those which can diffuse by simple diffusion and those that cannot.