Mitochondria are the energy producing organelles in prokaryotic cells. They are found in a cell's cytoplasm along with other organelles. They carry out many vital reactions and are involved in cellular processes such as cellular respiration. Mitochondria are also thought to cause diseases when they fail. When this happens, the lack of energy kills cells in the body, which could be fatal.
The theory of endosymbiosis states that mitochondria were once free living organisms. It is believed that they used anaerobic respiration to make their energy. As evolution took place, plants were formed which made oxygen; allowing for the start of aerobic respiration. Mitochondria adapted so that they could use this much more efficient form of energy production. It is thought that over time, the mitochondria were engulfed by large anaerobic cells; which then used the mitochondria to make its own energy.
Mitochondria are found in most body and plant cells. They produce energy, in the form of ATP, needed by cells. The energy stored in the cellular bonds is converted to ATP through a process called cellular respiration. In cellular respiration, ATP is produced mainly by the electron transport chain but it is also made by glycolysis and the Krebs Cycle. Glycolysis, which happens in the cytoplasm, and the Krebs Cycle, which takes place in the mitochondria both feed electrons into the Electron Transport Chain, in the mitochondria. The Electron Transport Chain uses a series of oxidation reduction reactions . This process moves electrons from one protein component to the next. This eventually produces the energy that is used to change ADP, Adenosine Di-Phosphate, to ATP. The number of mitochondria found in cells varies widely and can range from one large mitochondrion to thousands of small mitochondria. They are still the only organelles that have their own DNA.
Research is being done on the role mitochondria play in certain diseases. Some mitochondrial diseases...