Green Mitochondria (IMAGE) University of California - San Diego Caption Mitochondria (green) within a cell are depicted in this colorized transmission electron micrograph. The folds are called cristae, and are where chemical reactions occur that produce energy for cellular and metabolic functions. Credit Thomas Deerinck, National center for Microscopy and Imaging Research, UC San DIego Usage Restrictions Use photo credit License Original 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.