ROS production during cellular respiration. Cellular respiration is the process by which food molecules react with oxygen and are broken down to carbon dioxide and water with a net gain of captured energy in the form of ATP molecules. In about 5 percent of the time, oxygen is reduced to highly reactive superoxide. This is probably due to a “leak” of single electrons at a particular site of the mitochondrial electron transport chain. When superoxide undergoes further reduction, H2O2 and the extremely reactive hydroxyl radical is formed. It happens spontaneously or under the influence of various enzymes. The transition from H2O2 to hydroxyl radicals is favored in the presence of metals such as iron or copper. It also happens during abnormal exposure to ionizing radiation.
No comments:
Post a Comment