Portal:Mitochondria
Welcome to the Mitochondria portal. This portal is dedicated to the goal of applying community intelligence to the annotation of mitochondrial pages, including biological processes, biomedical application, gene and protein structure and function. Template:/box-footer
The mitochondrion (plural mitochondria) is a double membrane-bound organelle found in most eukaryotic cells. The word mitochondrion comes from the Greek μίτος, mitos, i.e. "thread", and χονδρίον, chondrion, i.e. "granule" or "grain-like". Mitochondria range from 0.5 to 1.0 μm in diameter. Considerable variation can be seen in the structure and size of this organelle. Mitochondria are described as "the powerhouse of the cell" because they generate most of the cell's supply of adenosine triphosphate (ATP), used as a source of chemical energy.
Template:/box-header Peter Dennis Mitchell, Fellow of the Royal Society (29 September 1920 – 10 April 1992) was a British biochemist who was awarded the 1978 Nobel Prize for Chemistry for his discovery of the chemiosmotic mechanism of ATP synthesis.
In the 1960s, ATP was known to be the energy currency of life, but the mechanism by which ATP was created in the mitochondria was assumed to be by substrate-level phosphorylation. Mitchell's chemiosmotic hypothesis was the basis for understanding the actual process of oxidative phosphorylation. At the time, the biochemical mechanism of ATP synthesis by oxidative phosphorylation was unknown.
Mitchell realised that the movement of ions across an electrochemical potential difference could provide the energy needed to produce ATP. His hypothesis was derived from information that was well known in the 1960s. He knew that living cells had a membrane potential; interior negative to the environment. The movement of charged ions across a membrane is thus affected by the electrical forces (the attraction of positive to negative charges). Their movement is also affected by thermodynamic forces, the tendency of substances to diffuse from regions of higher concentration. He went on to show that ATP synthesis was coupled to this electrochemical gradient.
His hypothesis was confirmed by the discovery of ATP synthase, a membrane-bound protein that uses the potential energy of the electrochemical gradient to make ATP.
Transmission electron microscope image of a thin section cut through an area of mammalian lung tissue. The high magnification image shows a mitochondrion.
- July 2015, Salk Institute: Dietary fat intake could potentially ease mitochondrial disease. Link to source
- June 2015, American Society for Human Genetics: NGS technology helps identify new mitochondrial disease gene. Link to source
- April 2015, Children's Hospital of Philadelphia: Novel findings may hold promise for children, adults with mitochondrial disorders. Link to source
- ... that mitochondria are the central source of energy for all cell types?
- ... the electron transport chain is associated with the inner mitochondrial membrane and has 5 multi-protein complexes?
- ... that mitochondria are responsible for cardioprotection against ischemia-reperfusion injury?
- ... that the outer mitochondrial membrane is semi-permeable to water and solutes whereas the inner membrane is relatively impermeable?
- ... that the mitochondrial proteome hosts more than 1,500 proteins?
- ... that mitochondria make up 45% of the cellular volume of muscle cells (heart and skeletal) and only 3% in skin cells?
- ... that 98% of the mitochondrial proteome is encoded by genes in the nuclear genome and only 13 mitochondrial proteins are encoded by genes in the mitochondrial genome?
Here are some ways you can help out:
- Create new pages for missing topics, including mitochondrial function, disease, and genes/proteins
- Find, fix, and expand on stubs: Cell biology stubs; Biochemistry stubs; Genetics stubs; Disease stubs; Anatomy stubs
- Clean up pages needing attention: Biology pages
- Provide expertise on pages that require peer review
 |
 |
 |
 |
| Cellular processes | Cell anatomy | Diseases and disorders | Genetics |
 |
 |
 |
 |
 |
 |
| Biology | Biotechnology | Chemistry | Medicine | Neuroscience | Science |
- What are portals?
- List of portals
- Featured portals
