Using this equation, explain how you will know that photosynthesis is occurring during the experiments you reviewed in the lab notebook.
The correct answer and explanation is :
In a laboratory setting, photosynthesis can be monitored by using the following equation:
$$
6CO_2 + 6H_2O + light \ energy \longrightarrow C_6H_{12}O_6 + 6O_2
$$
This equation represents the process by which plants, algae, and some bacteria convert carbon dioxide and water into glucose (C₆H₁₂O₆) and oxygen, using light energy from the sun. To determine if photosynthesis is occurring during an experiment, there are several indicators you can observe:
- Oxygen Production: Oxygen is one of the byproducts of photosynthesis. During experiments where photosynthesis is being studied (such as with aquatic plants), you can measure the oxygen released into the surrounding environment. This can be done by collecting the oxygen in a closed system, using a gas syringe, or observing the formation of bubbles in aquatic plants like Elodea. If oxygen is produced, it indicates that photosynthesis is taking place.
- Glucose Production: Glucose, the main product of photosynthesis, can be measured by testing the presence of starch, a polysaccharide made from glucose. In the lab, after the plant is exposed to light for some time, the plant is boiled to kill it, then treated with iodine, which stains starch a blue-black color. If the plant tissues show this coloration, it indicates that glucose has been converted into starch and stored, signaling that photosynthesis has occurred.
- Change in Carbon Dioxide Levels: Carbon dioxide is one of the reactants in photosynthesis. In some experiments, the concentration of CO₂ in the environment can be measured. A decrease in CO₂ levels during the experiment suggests that photosynthesis is occurring because the plant is using CO₂ to produce glucose.
By tracking these factors, such as oxygen production, glucose conversion, and CO₂ consumption, you can confirm that photosynthesis is actively occurring during your experiments.