Sinh học - Chapter 9: Cellular respiration: harvesting chemical energy

When these bonds shift from nonpolar to polar, the electrons move from positions equidistant between the two atoms for a closer position to oxygen, the more electronegative atom. Oxygen is one of the most potent oxidizing agents. An electron looses energy as it shifts from a less electronegative atom to a more electronegative one. A redox reaction that relocates electrons closer to oxygen releases chemical energy that can do work. To reverse the process, energy must be added to pull an electron away from an atom.