Photosynthesis: How Plants Make Their Own Food (And Ours)
5th grade · 45 min · Science
Objective. Students will identify the three inputs of photosynthesis (sunlight, water, carbon dioxide) and the two outputs (glucose, oxygen), and explain why plants matter for the air we breathe.
OverviewH+C
Students learn that plants make their own food through photosynthesis, a process that uses sunlight, water, and carbon dioxide to produce glucose and oxygen. The lesson builds from a warm-up observation through guided note-taking, a live demonstration showing the plant releasing water vapor, and ends with an exit ticket connecting photosynthesis to the air students breathe.
Lesson stepsH
Step 1 · 5 minAI-generated — review
Teacher: Hold up the plant. Ask: 'If I forgot to water this for a month, what would happen?' Let students picture it. Then: 'What if I put it in a closet with no light for a month — same problem, or different problem?'
Students: Respond verbally. Some will say 'it dies' for both — press them to explain WHY each one kills the plant.
Step 2 · 10 minscaffolded
Teacher: Introduce 'photosynthesis' and write the equation in plain language: sunlight + water + CO2 → glucose + oxygen. Emphasize: 'Plants make their own food. They don't go to the grocery store.'
Students: Copy the equation onto the diagram handout. Color inputs and outputs.
Step 3 · 8 minscaffolded
Teacher: Demonstrate: seal the plastic bag around one leaf. Explain students will check it at the end.
Students: Watch demo. Predict what they'll see.
Step 4 · 12 minscaffolded
Teacher: Pair students. Each pair fills a 3-column chart: INPUT | SOURCE | WHY NEEDED. Circulate.
Students: Work with partner to complete chart.
Step 5 · 5 minscaffolded
Teacher: Reveal the bag. Ask: 'What do you see? What does that tell us?'
Students: Observe condensation. Discuss what it proves.
Step 6 · 5 minscaffolded
Teacher: Distribute exit tickets. Students complete individually.
Students: Complete the exit ticket.