mitochondrion

[mahy-tuh-kon-dree-uhn]

noun

Cell Biology.

1. the singular of mitochondria.

mitochondrion

/ 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

mitochondrion

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

mitochondrion

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

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

Word History and Origins

Origin of mitochondrion¹

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

Word History and Origins

Origin of mitochondrion¹

C19: New Latin, from Greek mitos thread + khondrion small grain

Example Sentences

In the brain, blocking this cleanup leads to a buildup of faulty mitochondria that release toxins and trigger neuron death, worsening memory loss and cognitive decline.

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Until now, scientists understood brown fat’s heat production mainly through mitochondria, the energy centers of cells.

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These are not thought to be connected to defective mitochondria.

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The pro-nuclei are removed from both embryos and the parents' DNA is put inside the embryo packed with healthy mitochondria.

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“The mitochondria is your bioenergetics, so your energy in your body is produced by all of the mitochondria in your cells,” Beheshti said.

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