Mitochondria are any cellular organelles that are located outside the nucleus of a cell. Mitochondria use cellular respiration to produce energy for these cells. They contain high levels of enzymes, fats and proteins.
Mitochondria have several other important cellular functions. These include generating heat, storing calcium used in cell signaling and regulating the growth of cells.
The word mitochondrion is New Latin and originates from the Greek words mitos, meaning thread, and chondrion, a diminutive word for grain. The first known use of mitochondria was in 1901.Learn more about Cells