Mitochondria << `my ` tuh KON dree uh >> are the parts of a cell that convert chemical energy from food into a form of energy the cell can use. Mitochondria use energy released by the breakdown of carbohydrates and fats. They use it to make a compound called adenosine triphosphate (ATP). Cells use ATP to power movement, transport substances into or out of the cell, and create chemicals that cells need to grow and divide. In many cells, mitochondria appear as spheres or short rods outside the nucleus. In others, they may form a network of small tubes.
Mitochondria are essential for the proper growth and function of nearly all cells. Defects in mitochondria can cause some forms of blindness, deafness, intellectual disability, and neuromuscular disease. Some scientists believe that decreased activity of mitochondria in the cells over time is responsible for some diseases associated with aging. Such diseases may include Parkinson’s and Alzheimer’s disease.
Mitochondria contain their own DNA (deoxyribonucleic acid) separate from the DNA in the cell’s nucleus. The DNA of the nucleus contains hereditary material from both parents. Mitochondrial DNA, on the other hand, in animals and human beings is inherited only from the mother. This separate DNA is useful to biologists. They can analyze it to help determine evolutionary relationships among living things.
See also Cell (The cytoplasm) (Producing energy); DNA.
