Active Transport Homeostasis

Overview

In lesson 13 of the unit, students compare passive and active transport across cell membranes. They apply the roles of concentration gradients, membrane proteins and ATP to explain how transport processes help cells maintain stable internal conditions.

Learning intentions

Students will:

• distinguish between passive and active transport.
• explain how concentration gradients influence the direction of movement.
• describe how membrane proteins and ATP enable active transport.
• relate membrane transport to cellular homeostasis.

Success criteria

• I can identify whether a transport process is passive or active.
• I can use the terms concentration gradient, membrane protein and ATP accurately.
• I can explain why active transport requires energy.
• I can connect membrane transport to maintaining stable conditions inside a cell.

Curriculum links

• Cells as the basis of life: explain how cell structures enable biological processes needed for life.
• Cell structures and functions: explain how the selectively permeable cell membrane and membrane proteins support transport.
• Cells and their environments: relate movement of substances across membranes to changing concentration conditions.
• Cells to systems: connect cellular regulation with the maintenance of stable internal conditions in multicellular organisms.

Lesson structure (60 minutes)

1. 0–7 min · Hook and retrieval. Display a diagram of two compartments separated by a membrane, with different concentrations of particles, using the hook and retrieval slides. Students individually predict which way particles will move and answer two retrieval questions about the phospholipid bilayer and diffusion, then compare answers with a partner.

2. 7–18 min · Explicit teaching. Use the transport comparison slides to model simple diffusion, facilitated diffusion and active transport. Teacher emphasises that passive transport moves substances down a concentration gradient without ATP, while active transport moves substances against a gradient using a specific membrane protein and ATP. Students complete a comparison table on the transport comparison worksheet.

3. 18–32 min · Group classification task. Organise students into seven groups of five and display the task instructions from the classification task slides. Each group sorts six teacher-provided scenario cards or diagrams into passive transport, active transport or insufficient information, recording evidence for every decision on the worksheet. Teacher circulates, questioning groups about gradient direction, protein involvement and energy use.

4. 32–44 min · Application: maintaining homeostasis. Present a cell scenario from the homeostasis scenario slides: a cell must maintain a higher internal concentration of a useful ion than its surroundings. Students annotate a membrane diagram on the worksheet to show the ion’s movement, the transport protein and ATP use, then write two sentences explaining how this helps maintain stable internal conditions.

5. 44–54 min · Exam-style response and feedback. Students independently answer: “Explain how active transport across a cell membrane contributes to homeostasis.” They must use the terms concentration gradient, membrane protein and ATP. Teacher displays a response structure on the exam-response and peer-check slides. Students exchange responses and use the checklist to identify one accurate explanation and one improvement.

6. 54–60 min · Plenary and exit check. Revisit the opening prediction using the plenary slides. Students complete the final three questions on the final check section, including a transport classification, a reason ATP is required for active transport, and one link to homeostasis. Collect worksheets to identify misconceptions for the next lesson.

Resources

• the complete transport and homeostasis slide deck
• the transport comparison and application worksheet
• Teacher-prepared transport scenario cards or diagrams
• Whiteboard and markers
• Projector or interactive display
• Coloured pens or highlighters
• Timer
• Exit response collection tray

Assessment

• Listen to group explanations during classification and check whether students correctly use gradient direction, membrane proteins and ATP as evidence.
• Review annotated membrane diagrams and the exam-style response for a logical link between active transport and stable internal conditions.
• Use the final worksheet questions as an exit check. Record students needing support with passive versus active transport, or with explaining homeostasis rather than simply defining it.

Differentiation

• Provide a partially completed comparison table, a labelled membrane diagram and sentence starters such as “The substance moves from…”, “This is active transport because…” and “Homeostasis is supported by…”.
• For students requiring additional support, colour-code arrows for movement down or against a concentration gradient and allow verbal rehearsal before writing. Pre-teach and display the terms gradient, selectively permeable, protein pump and ATP.
• Support EAL/D students with a visual word bank, clear paired discussion and permission to annotate diagrams before composing written explanations.
• Extend capable students by asking them to explain why facilitated diffusion still remains passive, despite requiring a membrane protein, and to predict what would happen if ATP production stopped.