1. Lab 5: Photosynthesis

2. Photosynthesis Background
Plants undergo photosynthesis to convert sunlight energy to usable chemical energy in the glucose molecule.
This process requires the reactants carbon dioxide and water. It yields in the presence of sunlight, enzymes and chlorophyll, the products glucose and oxygen.

3. Today we are going to investigate the process of photosynthesis in Elodea plants using simple chemical indicators.

4. Materials 2 Glass bottles (1) 150ml beaker
Aluminum foil (enough to cover one glass bottle)
6cm Elodea sprig
Bromothymol Blue (CO2 indicator)
Photosynthetic lights
Drinking straw
Graduated cylinder

5. Procedure
Obtain two empty bottles and two sprigs of Elodea (5-6cm each).
Add 35ml of H2O to the bottles.
Add 1ml of Bromothymol blue to the water in the bottles.
Take a deep breath and hold for 5 seconds. Then using a drinking straw exhale into both bottles for twenty seconds.
Observe the bottle and note any changes on the assessment table.
Add one sprig of Elodea to each bottle and seal with the cap.
Cover one bottle completely in tin foil so absolutely no light can enter the bottle. Leave the other bottle exposed to light.
Place both bottles under the photosynthetic lights in the prep room for 24hrs.
Record any changes after the 24 hrs.