Does Carbon Dioxide Play Double in Photosynthesis? Researchers from Sweden's Umeå University discovered that bicarbonate ion (HCO3-), the ionic form of carbon dioxide, has a regulatory function in the breakdown of water into H2 and O2 during photosynthesis. So carbon dioxide isn't just turning into sugar.
We have known since primary school years that food is obtained from carbon dioxide during photosynthesis. Another thing that few of us know is that carbon dioxide affects the rate of electron transport in the process of photosynthesis and thus the rate of oxygen production. This result was first published in 1931 by Otto Warburg, Nobel Prize winner in 1958, and his collaborator Krippdahl. At that time, these two said that the source of the oxygen produced by the plants was carbon dioxide, but it was understood years later that this idea was not correct and that the source of the oxygen released into the atmosphere was water.
There have been years of disagreement among researchers about the effect of carbon on electron transport in photosynthesis. Johannes Messinger, one of the team that carried out the study published in the Proceedings of the National Academy of Sciences, states that the results of the research will end the discussions. The team says that with a very sensitive technique they developed, they found that CO2 from two different types of carbon that emerges in the carbonic acid cycle acts as the final electron acceptor at the end of the photosynthetic reaction, and HCO3- acts as a proton acceptor at the beginning of the reaction.
Source : İbrahim Özay Semerci (www.tubitak.gov.t is )