Pyruvate dehydrogenase enzyme. Illustration of the molecular structure of the enzyme pyruvate de- hydrogenase, important in glycolysis. In the biochemical pathway of glycolysis, glucose is converted to pyruvic acid with the production of the energy carrier ATP. In this way the body powers itself. The enzyme pyruvate dehydrogenase facilitates this breakdown of the glucose molecule and as a dehydrogenase, causes the release of hydrogen atoms. Enzymes are protein catalysts which are responsible for speeding up the rate of biochemical reactions. Each enzyme is specific for a particular stage in a reaction.