Power Plants! - Harnessing the energy of chloroplasts
Jonathan Shim
David Thompson Secondary
Floor Location : M 224 E

This project aims to harness electricity from photosynthesis by extracting chloroplasts, as well as test the effects of light intensity on the voltage produced. It originated from a goal to improve photovoltaic cells by using nature’s power plants, chloroplasts. Normally, electrons in chloroplasts are transferred to NADP via a redox reaction, but NADP is not available when the chloroplasts are extracted. Instead, the electrons flow through a wire and voltage is measured by connecting a voltmeter. To extract the chloroplasts, pansy leaves were ground up with a mortar and pestle, then centrifuged for half an hour to create a small pellet of chloroplasts. The chloroplasts are then suspended in a phosphate buffer isolation medium and are then connected to the circuit for testing. It was determined that the voltage spikes briefly, characterized by a parabolic shape on a voltage graph, then decreases 75% of the way before climbing back up at a slower rate. Lifespan of the chloroplasts after extraction varies, from several minutes to a maximum of 26 hours. It was also extrapolated that if eight cells of the extract were connected together in series, the voltage would be about 1.6 V, more than a standard AA battery. Finally, it was determined that the light intensity affects the voltage produced, with an optimal light intensity.