Photosynthesis: The Plant Kitchen

• newEditor
• Science
• Primary Education
• Age 9,10

Photosynthesis: The Plant Kitchen

What do you already know about photosynthesis?

Learning Objective

At the end of the lesson you will be able to explain photosynthesis, describe the role of leaves, chlorophyll, and chloroplasts, identify the importance of stomata and glucose, perform a starch test, and discuss why photosynthesis is important for life.

Recall: What is Photosynthesis?

Think-pair-share: What have you heard about how plants make their own food?

What is Photosynthesis?

Definition

Photosynthesis is how plants make food using sunlight, water, and carbon dioxide.

Where?

It happens mostly in the leaves of green plants.

Leaves: The Plant Kitchen

Leaves are often called the ‘kitchen’ of the plant because they make food for the whole plant.

Parts of a Leaf

Leaves have veins, a blade, and tiny holes called stomata.

Chlorophyll: The Green Pigment

Chlorophyll is what makes leaves green. It helps capture sunlight for photosynthesis.

Chloroplasts: The Food Factories

Chloroplasts are tiny cell parts where photosynthesis happens. Each chloroplast contains chlorophyll.

The Role of Stomata

Stomata are small holes on the underside of leaves. They allow air (CO₂) and water vapour to move in and out.

What is Made During Photosynthesis?

Plants use sunlight, water, and CO₂ to make glucose (sugar) and oxygen.

The Photosynthesis Equation

Carbon dioxide + Water + Sunlight → Glucose + Oxygen (6CO₂ + 6H₂O + sunlight → C₆H₁₂O₆ + 6O₂)

Where Do Plants Store Food?

Plants store extra food as starch in roots, stems, leaves, fruits, and seeds.

Glucose and Starch

Glucose

Starch

The main sugar made during photosynthesis. Used for energy and growth.

Plants join together glucose molecules to make starch for storage.

Starch Test Experiment

We use iodine solution to test for starch in a leaf. A leaf turns blue-black if starch is present.

Sunlight is Needed: Experiment

If a leaf is covered and kept away from light, it will not turn blue-black with iodine—showing sunlight is necessary for photosynthesis.

Importance of Photosynthesis

Photosynthesis produces oxygen and food. It supports all animal life, including humans.

AFL: Quick Quiz

1. What does chlorophyll do? 2. Where does photosynthesis happen? 3. What are the products of photosynthesis?

Discuss: Why is Photosynthesis Important?

In pairs, list three reasons why photosynthesis is important for living things. Share your answers with the class.

Differentiated Activities

1. Draw the stages of photosynthesis and label key parts. 2. Write a story from the perspective of a leaf. 3. Create a poster explaining why we need photosynthesis.

Plenary: Reflect and Summarise

Write three facts you learned today and one question you still have about photosynthesis.

Exit Ticket

Before you leave, answer: Why do plants need sunlight? Hand in your response.

Write down 3 things you learned in this lesson.

Write down 2 things you want to know more about.

Ask 1 question about something you haven't quite understood yet.