Can you visualize the consumption of carbon dioxide by a plant leaf while it engages in photosynthesis? This is the driving question the biology students answered this week.
The students started off with the background information that when carbon dioxide is dissolved in a liquid, it becomes acidic and a pH indicator solution will change color from blue to green/yellow. When the carbon dioxide is removed from the liquid, the pH will rise above 6.76, and the solution will turn blue again.
Like most science lab protocols, the students hypothesized about the level of carbon dioxide dissolved in water when an aquatic plant is photosynthesizing. Then, they added carbon dioxide to the water in their test tubes by blowing bubbles into the tubes.
The next step was to add a piece of an aquatic plant to one of the test tubes and set both test tubes in a brightly lit place to let them photosynthesize. After 48 hours, the students were asked to examine the color of their test tubes.
This observation activity was very important in setting down the fundamentals of a science experiment. From hypothesizing to conducting the procedure to logging data, the biology students practiced being patient scientists. They also learned to trust the process because not every science experiment can happen immediately. The students were able to learn about photosynthesis and take part in the actual process, which added a fun element to the lesson.