Over the years, the safety of many food additives, from food dyes to trans fats, has come into question. A scare over a food additive may linger in our minds long after researchers find that there's actually no cause for alarm.
In cell biology, a mitochondrion (plural mitochondria) is an organelle found in most eukaryotic cells. Mitochondria are sometimes described as cellular power plants, because their primary function is to convert organic materials into energy. Note: The above text is excerpted from the Wikipedia article Mitochondrion, which has been released under the GNU Free Documentation License.
Mitochondria are found exclusively in eukaryotic cells. These organelles are often called the power plants of the cell because their main job is to make energy (ATP). Mitochondria are highly unusual--they contain their own genetic material and protein-making machinery enwrapped in a double membrane.