See Also: Mitochondrial(medicine)
DNA, mitochondrial(medicine)
DNA, mitochondrial(health)
mitochondrial matrix(medicine)
disease, mitochondrial(medicine)
mitochondrial disease(medicine)
Genome, mitochondrial(health)
mitochondrial chromosome(medicine)
Mitochondrial heteroplasmy(health)
mitochondrial gene(medicine)

DNA, mitochondrial (health)


Mitochondrial DNA (mtDNA) is the DNA of the mitochondrion, a structure situated in the cytoplasm of the cell rather than in the nucleus (where all the other chromosomes are located). All mtDNA is inherited from the mother. There are 2 to 10 copies of the mtDNA genome in each mitochondrion. mtDNA is a double-stranded, circular molecule. It is very small relative to the chromosomes in the nucleus and so contains only a limited number of genes. It is specialized in the information it carries and encodes a number of the subunits in the mitochondrial respiratory-chain complex that the cell needs to respire. (It also contains genes for some ribosomal RNAs and transfer RNAs). Mutations (changes) in mtDNA can cause disease. The mutations often impair the function of oxidative-phosphorylation enzymes in the respiratory chain. This is especially manifest in tissues with a high energy expenditure such as brain and muscle.