In one type of redox reaction, a hydrogen molecule (in the form of hydride anion plus a proton) is transferred to or from organic compound: these are called hydrogenation and dehydrogenation reactions...In one type of redox reaction, a hydrogen molecule (in the form of hydride anion plus a proton) is transferred to or from organic compound: these are called hydrogenation and dehydrogenation reactions. We will see several examples of important oxygenase reactions in the central metabolic pathways, but for most of these, detailed mechanistic discussion is outside the scope of this text.