mitochondrion (redirected from Chromosome mitochondria (human))

mi·to·chon·dri·on (mt-kndr-n) n. pl. mi·to·chon·dri·a (-dr-) A spherical or elongated organelle in the cytoplasm of nearly all eukaryotic cells, containing genetic material and many enzymes important for cell metabolism, including those responsible for the conversion of food to usable energy. It consists of two membranes: an outer smooth membrane and an inner membrane arranged to form cristae. mito·chondri·al (-dr-l) adj.

mitochondrion cutaway view

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mitochondrion

[mī′tōkon′drē·on] pl. mitochondria

Etymology: Gk, mitos, thread, chondros, cartilage

a rodlike, threadlike, or granular organelle that functions in aerobic respiration and occurs in varying numbers in all eukaryotic cells except mature erythrocytes. It is bounded by two sets of membranes, a smooth outer one and an inner one that is arranged in folds, or cristae, that extend into the interior of the mitochondrion, called the matrix. Mitochondria provide the principal source of cellular energy through oxidative phosphorylation and adenosine triphosphate synthesis. They also contain the enzymes involved with electron transport and the citric acid and fatty acid cycles. Mitochondria are self-replicating and contain their own DNA, RNA polymerase, transfer RNA, and ribosomes. Also called chondriosome. mitochondrial, adj.

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mitochondrion

singular of mitochondria.

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mitochondrion

An organelle in the cytoplasm of cells, which produces most of the energy-rich molecule adenosine triphosphate (ATP) in cells. It is produced by using oxygen to break down nutrient molecules (e.g. glucose). The number of mitochondria in a cell varies, it is greater in active cells, such as muscle and liver cells which need more ATP. Mitochondria are involved in other processes (e.g. apoptosis, cellular proliferation). Each mitochondrion contains DNA, RNA, ribosomes and granules. The DNA is distinct from that of the cell nucleus. Mitochondrial DNA is inherited only through the female. Mutations in mitochondrial DNA causes genetic disorders (e.g. Leber's hereditary optic atrophy). Plural: mitochondria.