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

3. Anatomy of a Leaf

4. 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

5. 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.

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

7. 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

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