Human mitochondria in health, disease, ageing and cancer.

ABSTRACT

In every human cell there are hundreds of mitochondria, which are required for oxidative phosphorylation as well as many other metabolic processes. Each mitochondrion contains approximately 5 mitochondrial DNA molecules. These circular DNAs of 16.5 kb in size contain only 39 genes. Mutations in mitochondrial DNA are responsible for many diseases. Alterations in these molecules may also play a role in ageing and in tumour formation.