Measure Photosynthesis with Floating Leaves

Introduction

Do you know how plants get the energy they need to grow and reproduce? They do not eat like humans and animals do; they make their own food with a process called photosynthesis. During photosynthesis, plants convert light, water, and carbon dioxide from the air into oxygen and sugars. In this activity, you will be able to observe the oxygen production in leaves by doing a floating leaf disk experiment. You can also find out how quickly plants produce oxygen, and what variables affect photosynthesis. How much do you think light matters?

Credits

Materials

• Transparent cups, 4 or more
• Permanent marker
• Baking soda
• Measuring cup
• Water
• 1/8 or 1/4 teaspoon
• Dish soap
• Light source (a bright light works best)
• Single-hole puncher
• Plant leaves (spinach or ivy leaves work best)
• Plastic syringe, 10-mL or bigger (without the needle)
• Aluminum foil
• Paper towels
• Timer
• Lab notebook
• Pencil or pen
• Optional: Adult helper