Mitochondria is essential to generate metabolic energy in eukaryotic cells as well as to regulate calcium buffering, cell signaling, the production of reactive oxygen species (ROS), and apoptosis. They mainly produce most of the cellular energy derived from the breakdown of carbohydrates and fatty acids, which is consequently converted to ATP via oxidative phosphorylation. Mitochondria are also distinctive among the cytoplasmic organelles in that they contain their own DNA, which encodes limited number of mitochondrial proteins, tRNAs, and rRNAs.