Organelle · double membrane
Mitochondria
The power plants
In view
It opens to show the outer membrane, the inner membrane and its cristae. Cool tints mark where protons are pumped, between the membranes and inside each crista; warm marks the matrix they flow back into. Mitochondria ride along microtubules and often fuse into branching networks. Real cells pack about a tenth of their cytoplasm with them; fewer are drawn here so you can see past them.
Mitochondria burn sugars and fats with oxygen and store the energy as ATP, the cell’s universal fuel. The inner membrane folds inward into cristae, joined to the rest of it only by narrow crista junctions. Respiratory chains in the cristae pump protons out of the matrix, and ATP synthase, a rotary motor lined up in rows along the curved crista edges, lets them flow back and turns that flow into ATP.
They even carry their own DNA, a relic of the bacteria they once were, packed with the protein TFAM into nucleoids about 100 nm across.
- Typical size
- ≈ 1 × 2 µm
- Per cell
- ≈ 1,000 – 10,000
- Own DNA
- 16,569 bp · 37 genes
- ATP synthase
- 3 ATP per turn
Did you know?
You recycle roughly your own body weight in ATP every single day, almost all of it made in mitochondria.
Sources
- How big are mitochondria? · Milo & Phillips · Cell Biology by the Numbers
- Structure and function of mitochondrial membrane protein complexes · Kühlbrandt 2015 · BMC Biol
- 7.4 Oxidative Phosphorylation · OpenStax · Biology 2e
- Association of mitochondria with microtubules in cultured cells · Heggeness et al. 1978 · PNAS
- Mitochondrial growth and division during the cell cycle in HeLa cells · Posakony et al. 1977 · J Cell Biol
- 4.3 Eukaryotic Cells · OpenStax · Biology 2e
- Resolution of distinct rotational substeps by submillisecond kinetic analysis of F1-ATPase · Yasuda et al. 2001 · Nature
- The Nobel Prize in Chemistry 1997 · NobelPrize.org
- Dimer ribbons of ATP synthase shape the inner mitochondrial membrane · Strauss et al. 2008 · EMBO J
- Macromolecular organization of ATP synthase and complex I in whole mitochondria · Davies et al. 2011 · PNAS
- Sequence and organization of the human mitochondrial genome · Anderson et al. 1981 · Nature
- The Origin and Diversification of Mitochondria · Roger et al. 2017 · Current Biology
- Super-resolution microscopy reveals that mammalian mitochondrial nucleoids have a uniform size and frequently contain a single copy of mtDNA · Kukat et al. 2011 · PNAS
- Mitochondrial DNA · MedlinePlus Genetics (NIH)
- Daily turnover of ATP · BioNumbers · BNID 105606