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mitochondria

noun, plural form of mitochondrion

Mitochondria are spherical or rod-shaped organelles found within the cytoplasm of eukaryotic cells. They are regarded as the “powerhouse of the cell” because they are the cell’s main generator of high-energy compounds (e.g. ATP). They produce large amounts of energy through oxidative phosphorylation of organic molecules (see cellular respiration). That is, they are capable of using glucose and oxygen to produce energy (and releasing carbon dioxide and water in the process) for use in many metabolic processes. Thus, it is not surprising to find several mitochondria in high energy-requiring cells, such as muscle cells.

They are semi-autonomous, self-reproducing organelles because they contain their own genome. In fact, their DNA has become an important tool in tracking genetic histories since their genetic material is present in only one copy, and does not recombine in reproduction.

According to the endosymbiotic theory, mitochondria could have been remnants of early bacteria engulfed by ancient eukaryotic cells a billion years ago, which might have evolved and become energy-yielding structures within eukaryotic cells at present.

Also known as chondriosome

Word origin: from Gk. mitos - thread + khondrion - little granule