2. Light…Carbon Dioxide…Action! In today’s lab… * we will create a micro-environment to observe the actions of the carbon cycle * use an acid-base indicator to determine the amount of carbon dioxide in the environment * observe the effects of light energy on the progression of the carbon cycle

3. Materials 2 Ziploc bags label both with names and one LIGHT and the other DARK 2 sprigs of aquatic plant make sure both plant pieces are the same size 20 mL Bromothymol blue solution 10 mL per bag 1 straw

4. Bromothymol blue BASIC ACIDIC ACID-BASE indicator OxygenCarbon dioxide

5. LIGHTDARK Why do we blow into the straw? What makes the bromothymol blue solution change color? Why do we put one micro-environment in the light and one in the dark?

6. Procedure (1)Make sure you have all materials (2)Label both bags with your names and one bag LIGHT and the other DARK (3)Measure 20 mL of bromothymol blue solution (4)Pour the 10 mL of bromothymol blue solution into the bag labeled LIGHT; seal the bag (5)Repeat step(4) with the bag labeled DARK (6)Slightly open one bag and insert the straw; blow air into the solution until it turns yellow-green; quickly seal the bag (7)Repeat step (6) with the other bag (8)Quickly open each bag and place a sprig of plant inside; seal the bag (9)Write down your observations of each bag (10)Place the bag labeled LIGHT in the light and the one labeled DARK in the dark closet (11)CLEAN UP! (12)Return tomorrow to observe each bag; write down your observations