Photosynthesis

For 7th graders, photosynthesis is how plants, algae, and some bacteria make their own food (sugar) using sunlight, water, and carbon dioxide, releasing oxygen as a byproduct, a vital process that fuels most life on Earth. Plants capture light with chlorophyll in chloroplasts, absorb CO2 through leaf pores (stomata), and get water from roots, converting these into energy-storing glucose for growth and releasing oxygen that animals breathe. 

What it is: 

How it works (Step-by-step): 

1. Light Capture: Chlorophyll, the green pigment in chloroplasts (tiny parts inside plant cells), absorbs sunlight.
2. Water & CO2 Intake: Roots pull water from the soil; leaves take in carbon dioxide from the air through tiny holes called stomata.
3. The Conversion: Inside the leaves, sunlight's energy combines the water and carbon dioxide to make sugar (glucose).
4. Oxygen Release: Oxygen, a waste product for the plant, is released back into the air through the stomata. 

Why it's important: 

• Plant Food: The sugar (glucose) is the plant's energy to grow, make flowers, and produce fruits.
• Animal Food: Animals eat plants (or other animals that ate plants) to get this energy.
• Our Air: It produces the oxygen we and other animals need to breathe.