Respiration Enzyme Structure (IMAGE) RIKEN Caption This graphic shows a comparison of the overall structures of the respiration enzymes. (A) qNOR, (B) cNOR, and (C) COX. These enzymes share similar structure of the core region shown with rainbow color. Each catalytic site denoted by black dotted line contains heme molecule shown as a red stick. Credit RIKEN Usage Restrictions The image may only be used with appropriate caption or credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.