M I T O C H O N D R I A Part 2
ENERGY PRODUCTION AND OTHER VITAL FUNCTIONS OF MITOCHONDRIA FOR LIFE.
Energy production mechanisms of mitochondria by burning nutrients as fuel is not very well understood by scientists. In the 1960s, British biochemist Peter Mitchell discovered how electrons derived from carbon molecules in food substances combined with O2 in the cristae of mitochondria releasing a spark of energy that is captured as a gradient in electrical voltage across the membrane of mitochondria. This voltage provides the energy needed for all the processes in the body and the brain, including body temperature.
Mitochondria also produces a molecule called ATP (adenosine triphosphate) which works like a portable unit of energy that powers multiple biochemical reactions in each cell.
In recent years, research scientists realized the importance of mitochondria in health in the pathogenesis of disease formation and in the aging process. They setup independent research center dedicated to mitochondrial research. Among them, The Center for Mitochondrial and Epigenetic Research at Children’s Hospital of Philadelphia is well known.
Mitochondria specializes across organs and cell types. Mitochondria within a cell may look very different. For example, in neuron cells mitochondria found in the fiber of dendrites through which neurons receive signals from other neurons. Axonal mitochondria move along the linear axon. Cytoplasmic mitochondria cluster around the cell nucleus.
Research scientists using three D electronic tomography imaging were able to show that mitochondria are very active, moving and communicating with each other, behaving like their bacterial ancestors, cooperating, helping, and even exchanging and repairing each other, through their mitochondrial information processing system (MIPS).
It appears that mitochondrial junctions and alignment of cristae operate like brain cells (neurons) synaptic connections, and thereby, according to some scientist, acting like “an intra cellular third brain”.
To me, the concept of first, second, and the third brains, from the DNA stand point is much more interesting than their location. Our first commander-in-chief, the brain, is in the central nervous system (CNS) and created by human’s DNA. Our second brain is in our guts, which is inhabited by trillions of microorganisms with their own independent DNAs. And lastly, our third brain is in each cell represented by mitochondria with their own independent DNA. So then, it is fair to say that DNA has an ability to be wise, and create our first, second and third brains.
Mitochondrial information processing system (MIPS) sense hormonal, chemical and metabolic signals in the membrane potential of their cristae to produce messenger signals that is intelligible to the cell nucleus they inhabit. Genes sit inert in the nucleus until the required energy and signals come along to turn some of them on or off. Mitochondria are not only involved in integrating information but also give orders whether the cell divides, differentiates, or dies.
In conclusion, it could be said that mitochondria drive and influence health, diseases, and aging in several different ways. The first pathway derives from their role as ultimate energy processors. Any defect in this function produces signals for cell death, aging, and disease formation.
The second pathway derives from mitochondrial influence on gene activities and gene expressions.
The third pathway is easily causing diffuse inflammatory reaction. When cells are stressed or injured, they leak mitochondrial DNA into the circulation. A recent clinical study has shown that ICU patients have increased amount of mitochondrial DNA circulating in their blood. Because mitochondrial DNA resembles bacterial DNA, the immune system sees them as pathogens and reacts with intense inflammation. Chronic inflammation deteriorates organs’ functions and accelerates aging process.
For further reading: Martin Picard. The Social life of Mitochondria. Scientific American, June 2025.
