False color image of mitochondria [in the University of Pittsburgh colors of blue and gold]. The original transmission electron micrographs are actually in a range from white to black. CREDIT: Center for Biologic Imaging, University of Pittsburgh.
Three mitochondria (blue) fractured to reveal the internal structure.
The internal membranes (cristae — made visible here) are covered with enzyme complexes involved in the conversion of metabolites into energy.
The surrounding cytoplasm is shown in gold.