Photosynthesis process by which plants use energy from sunlight to produce glucose (sugar), which is later converted to chemical energy (ATP)

Anatomy of a Leaf

LIGHT Carbon Dioxide WATER OXYGEN *released into the air LIGHT GLUCOSE Chlorophyll Absorbs light *is formed and converted to ATP Carbon Dioxide WATER *absorbed from the roots *enters through stromata

Do Plants Consume or Release CO2? In this lab, you will use a pH indicator to determine if CO2 is being consumed or produced in a reaction within plants In the presence of light, plants perform photosynthesis and consume carbon dioxide. But does this also happen in the dark? To determine whether Carbon dioxide is consumed or produced, we will place elodea plants in either light or dark environment. The change in Carbon dioxide will be detected by the pH indicator.

pH Indicator neutral ACIDIC BASIC If CO2 increases, color will change in this direction If CO2 decreases, color will change in this direction

Procedure Pour equal volume of water into 4 test tubes (they should be filled about 2/3 full with your neutral solution). 2. Place a piece of elodea (cut end up) into 2 of the tubes 3. The other two test tubes serve as controls and will not have elodea 4. Seal one set (control test tube & elodea test tube) with aluminum foil and tape, and place in the dark 5. Seal the other set (control test tube & elodea test tube) with prafilm and place in area that gets a lot of light 6. Record the colors of the solutions in the test tubes after 1-2 days on your observation sheets

DARK CYCLE SUGAR Carbon Dioxide Stroma GLUCOSE Facilitates Dark Cycle GLUCOSE *absorbed from the roots Carbon Dioxide *enters through stromata