What are Mitochondria?

Muscle Cell Mitochondria © Dennis Kunkel

Mitochondria are the cell's power producers. They convert energy into forms that are usable by the cell. They are the sites of cellular respiration which ultimately generates fuel for the cell's activities. The number of mitochondria in a cell can range from a few to several thousand, depending on the type of cell.

Mitochondria are tubular or oblong shaped and are bounded by double membranes. The double membranes divide the mitochondrion into two distinct parts: the intermembrane space and the mitochondrial matrix. Mitochondria are semiautonomous in that they can divide and grow to make more of themselves. They also have their own DNA and ribosomes. To learn more about mitochondria and other cellular components, visit Journey into the Cell.