Richie Yang
Sir Winston Churchill Secondary
Floor Location : M 043 F

This project is to examine the effects of carbon dioxide on the light dependent reactions in photosynthesis. Spinach was used as the plant and photosynthesis facilitator, a lamp was used to provide light, and the spinach disks were dropped into a baking soda solution to provide carbon dioxide and water. The measurement of the rate of photosynthesis was done in how much time it took for ten out of twenty spinach discs to float. Three separate trials containing multiple concentrations were created to confirm the accuracy of the results. The results indicated that the concentration of Carbon dioxide did indeed have an immense influence on the light dependent reactions. Initial increases of CO2 concentration drastically decreased the duration of time needed for ten spinach discs to float. This indicates that the production of oxygen, a by-product in the light-dependent reaction, is greatly enhanced therefore revealing an enhanced rate in the light-dependent reaction. However, as the concentration of Co2 were further increased, its effect on the light dependent reactions were decreased. Conclusively, the experiment revealed that an increase in the concentration of CO2 will always enhance the rate of light dependent reactions in photosynthesis, but decreased in effectiveness as concentration is further increased.