Observing Photosynthesis
This is a very simple lab that allows students to observe the formation of oxygen bubble during photosynthesis. This lab can be done as a demonstration to begin the unit, or it can done as an inquiry lab where students try to devise an explanation for the bubbles they see in the test tube.
MATERIALS
- At least 2 test tubes
- At least 2 beakers of water
- Sprigs of elodea
- Light source (e.g. flash light)
- Aluminum foil
PROCEDURE
- Fill each available test tube with water
- Put one sprig of elodea into each test tube
- Invert the test tube in the beaker
- Place one beaker near the light source and wrap an aluminum foil around another beaker (optional, place another beaker away from the light source or somewhere dark)
- Wait for approximately 30 minutes and observe the formation of bubbles
EXTENSION
- Use phenol red to quantitatively analyze the presence and disappearance of carbon dioxide
SAFETY CONSIDERATIONS
- Goggles should be provided to students
- Wipe up spills immediately to prevent students from slipping and falling
- Phenol red is an eye irritant and slightly hazardous in case of skin contact. Extreme precaution should be taken if phenol red is used