Science lesson plan · 11th grade (Year 12 in England) · 45 minutes
Light-dependent reactions and the Calvin cycle
Plants
CCSS NGSS.HS-LS1-5England: A level Biology: Photosynthesis (extension)
Objective and success criteria
Students will: Light-dependent reactions and the Calvin cycle.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Photosynthesis: word and balanced symbol equations
Leads to: the next skill in this area.
Materials: Real plants or seeds, Hand lenses, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Photosynthesis: word and balanced symbol equations). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Which is the balanced symbol equation for photosynthesis? (C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O / CO₂ + H₂O → C₆H₁₂O₆ + O₂ / 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ / 6O₂ + 6H₂O → C₆H₁₂O₆ + 6CO₂) → 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂Prompt: Carbon dioxide and water are the reactants.
- A leaf makes 4 molecules of glucose by photosynthesis. Using 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂, how many water molecules are used? → 24Prompt: Read the numbers in front of each formula.
- Which substance in chloroplasts absorbs the light? (cellulose / chlorophyll / glucose / starch) → chlorophyllPrompt: It is a green pigment.
Hook · 5 min
- Bring in a plant that has been kept in the dark next to one in the light, and ask what happened.
- Share the objective: Light-dependent reactions and the Calvin cycle. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Which stage of photosynthesis: fixes carbon dioxide with the enzyme RuBisCO?
- Step 1: The Calvin cycle in the stroma fixes carbon dioxide using ATP and NADPH to make sugars.
- Step 2: So the answer is: Calvin cycle (light-independent)
- Answer: Calvin cycle (light-independent)
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Which stage of photosynthesis: happen on the thylakoid membranes? (light-dependent reactions / Calvin cycle (light-independent)) → light-dependent reactionsPrompt: Which stage needs carbon dioxide and which needs light energy directly?
- A plant is moved into darkness. Why does the Calvin cycle soon stop, even though it does not use light directly? (It runs out of ATP and NADPH from the light-dependent reactions / RuBisCO is destroyed by darkness / Carbon dioxide disappears in the dark / The stroma freezes) → It runs out of ATP and NADPH from the light-dependent reactionsPrompt: What does the Calvin cycle need from the first stage?
You do: independent practice · 10 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Which stage of photosynthesis: make ATP and NADPH? (light-dependent reactions / Calvin cycle (light-independent)) → light-dependent reactionsPrompt: Which stage needs carbon dioxide and which needs light energy directly?
- Where in the chloroplast is chlorophyll found? (in the outer membrane only / in starch grains / in the stroma / in the thylakoid membranes) → in the thylakoid membranesPrompt: Chlorophyll absorbs light for the first stage.
Watch out for
- Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
- Remembering facts without the reason: ask "why?" and "what is the evidence?"
Support and stretch
Support
- Review first: Photosynthesis: word and balanced symbol equations.
- Use concrete materials: real plants or seeds.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-11.
Free lesson plan from eurekami.com/lesson-plan-builder