The mitochondrion (plural mitochondria) is a membrane-enclosed structure found in most eukaryotic cells (the cells that make up plants, animals, and many other forms of life). Mitochondria range from 0.5 to 1.0micrometer (μm) in diameter. These organelles are sometimes described as "cellular power plants" because they generate most of the cell's supply of adenosine triphosphate (ATP), used as a source of chemical energy In addition to supplying cellular energy, mitochondria are involved in other tasks such as signaling, cellular differentiation, cell death, as well as the control of the cell cycle and cell growth. Mitochondria have been implicated in several human diseases, including mitochondrial disorders and cardiac dysfunction, and may play a role in the aging process. The word mitochondrion comes from the Greek μÎτος, mitos, i.e. "thread", and χονδρÎον, chondrion, i.e. "granule".
