Photosynthesis

• Photosynthesis is the process by which plants make their own food.

Why Study Photosynthesis?• Photo means light• Synthesis means put together.• Photosynthesis is how plants

make their own food

We all need photosynthesis!

• Directly or indirectly, all life on Earth depends on photosynthesis.– Plants take in carbon dioxide &release oxygen

which controls our atmosphere– Animals and humans need oxygen to breathe– Plants create their own food (sugar) to grow.– Animals and humans eat the plants for food and

energy– Plants provides energy - the energy stored in

petroleum, natural gas, coal, and firewood all came from plants which have stored the energy from the sun via photosynthesis

Photosynthesis• How green plants make their

own food• Plants Need

–Light - from the sun–Water - from roots–Carbon dioxide – from air,

enters plant through tiny openings under the leaves called stomata

–Chlorophyll: green color in plants that traps energy from sunlight to make food

Photosynthesis• A chemical reaction makes

glucose (sugar) and oxygen from the carbon dioxide and water

• The plant keeps the glucose (sugar) as the main source of nutrition or food for the plant; helps plant grow.

• The plant releases the oxygen into the atmosphere.