Photosynthesis



The most important job of a leaf is creating food for the tree by a process called photosynthesis. Photosynthesis uses sunlight, chlorophyll (which is what makes leaves green), water, and carbon dioxide to make sugar, which is food for the tree. Here's how it goes.

1. Tree roots absorb water from the soil and carry it to the leaf.  2. Carbon dioxide breathed out by people and animals is taken in to the leaves by the stomata.  3. The carbon dioxide is spread to the cells that contain chlorophyll.  4. Sunlight breaks down the water into hydrogen and oxygen.  5. The hydrogen works with the carbon dioxide to create food for the tree.  6. The oxygen is released for us to breathe.

This ThinkQuest has some graphics that might help you understand photosynthesis a little better. You can find more detailed information on photosynthesis on the Photosynthesis Page. When you're done looking at the page, you can take the Photosynthesis Quiz to see how much you've learned.