mitochondrion

American  

[mahy-tuh-kon-dree-uhn] / ˌmaɪ təˈkɒn dri ən /

noun

Cell Biology.

1. the singular of mitochondria.

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mitochondrion British  

/ ˌmaɪtəʊˈkɒndrɪən /

noun

1. Also called: chondriosome.  a small spherical or rodlike body, bounded by a double membrane, in the cytoplasm of most cells: contains enzymes responsible for energy production

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mitochondrion Scientific  

/ mī′tə-kŏn′drē-ən /

plural

mitochondria

1. A structure in the cytoplasm of all cells except bacteria in which food molecules (sugars, fatty acids, and amino acids) are broken down in the presence of oxygen and converted to energy in the form of ATP. Mitochondria have an inner and outer membrane. The inner membrane has many twists and folds (called cristae), which increase the surface area available to proteins and their associative reactions. The inner membrane encloses a liquid containing DNA, RNA, small ribosomes, and solutes. The DNA in mitochondria is genetically distinct from that in the cell nucleus, and mitochondria can manufacture some of their own proteins independent of the rest of the cell. Each cell can contain thousands of mitochondria, which move about producing ATP in response to the cell's need for chemical energy. It is thought that mitochondria originated as separate, single-celled organisms that became so symbiotic with their hosts as to be indispensible. Mitochondrial DNA is thus considered a remnant of a past existence as a separate organism.

2. See more at cell cellular respiration

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mitochondrion Cultural  

1. The cell organelle where much of cellular respiration takes place; the “power plant” of the cell.

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Discover More

Mitochondria probably entered eukaryotes by an act of endosymbiosis, in which one simple cell was absorbed by another.

Mitochondria contain their own DNA. It is by tracing the mitochondrial DNA, which individuals inherit only from their mothers, that genetic linkages are often traced. (See mitochondrial Eve.)

Other Word Forms

• mitochondrial adjective

Etymology

Origin of mitochondrion

First recorded in 1900–05; mitochondria ( def. )

Example Sentences

A major focus of this effort is the mitochondria, often called the powerhouse of the cell.

From Science Daily

The evidence suggests that structures such as the nucleus emerged well before mitochondria.

From Science Daily

A newly identified kind of DNA damage inside mitochondria, the small structures that supply cells with energy, may help explain how the body detects and reacts to stress.

From Science Daily

A key reason is the shrinking number of mitochondria, the small, organ-like structures inside cells that supply most of the energy a cell uses.

From Science Daily

The team pinpointed a protein that enables cancer cells to alter the shape of their mitochondria, the structures that generate cellular energy.

From Science Daily