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Authors: David Perlmutter M. D., Alberto Villoldo Ph.d.
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were first observed by the German pathologist Richard Altmann in 1890. Seen through a microscope, these small intracellular particles look like tiny, threadlike grains. Hence the name mitochondria, derived from the Greek mitos meaning “thread,” and chondrin , meaning “grain.” It was not until 1949, however, that the role of mitochondria, as the producers of cellular energy, was fully explained by two biological chemistry researchers, Eugene Kennedy of the Harvard Medical School and Albert Lehninger, then of the University of Wisconsin–Madison.
Mitochondria use carbohydrates as fuel, which they convert into life-sustaining energy with the by-products of water and carbon dioxide. This process is called oxidative metabolism , so named because oxygen is consumed in the process, just as oxygen is consumed by fire (as demonstrated when we extinguish a flame by smothering it and depriving it of oxygen).
But, unlike in a fire, which releases energy in an uncontrolled reaction, the energy, or life force, produced by mitochondria is stored in a chemical “battery,” a unique molecule called adenosine triphosphate (ATP). Energy-rich ATP can then be transported throughout the cell, releasing energy on demand in the presence of specific enzymes. 1
In addition to the fuel they produce, mitochondria also create a by-product related to oxygen called reactive oxygen species (ROS), also known as free radicals. 2
THE ROLE OF FREE RADICALS
These free radicals perform an important, positive function in human physiology. They play a pivotal part in regulating apoptosis , the process through which cells initiate self-destruction. Apoptosis happens when genetic switches that instruct a cell to die are turned on. While it may be puzzling to look upon cell death as a positive event, apoptosis is indeed a critical function that enables growth and healing of the greater organism.
Until quite recently, scientists pretty much subscribed to the paradigm that all cellular functions, including apoptosis, were directed by the cell nucleus. But, as Nick Lane notes in his compelling book, Power, Sex, Suicide, “there has been a change of emphasis that amounts to a revolution, overturning the nascent paradigm. The paradigm was that the nucleus is the operations centre of the cell, and controls its fate. In many respects this is of course true, but in the case of apoptosis it is not. Remarkably, cells lacking a nucleus can still commit apoptosis. The radical discovery was that the mitochondria control the fate of the cell: they determine whether a cell shall live or die.” 3 Mitochondria, then, must be looked upon as being so much more than simply organelles whose job involves turning fuel into energy. They wield the Sword of Damocles.
Hippocrates was the first to use the term apoptosis , which literally means “the falling of leaves from a tree.” However, apoptosis didn’t gain traction in the scientific community until the pathologist Alastair R. Currie published an important paper describing cellular self-destruction as a basic biological phenomenon. 4 Thereafter, researchers used apoptosis to describe the process through which the body intentionally eliminates cells in order to serve a larger purpose.
This process begins even while the fetus is in the womb. As an example, during embryonic development, human hands initially resemble the webbed appendages of a frog. But death of the cells in the webbed area transforms these extremities, allowing for definition of individual fingers and refinement of the entire hand.
Furthermore, after birth, apoptosis is the protocol that enables your body to continuously rid itself of as many as ten billion cells every day, making room for new, healthier cells. The outcasts include a multitude of cancer cells. Most of the time, when these pathogenic cells appear, mitochondria send a signal that tells them to die rather than replicate. This is a very important mitochondrial function because runaway
Mitochondria use carbohydrates as fuel, which they convert into life-sustaining energy with the by-products of water and carbon dioxide. This process is called oxidative metabolism , so named because oxygen is consumed in the process, just as oxygen is consumed by fire (as demonstrated when we extinguish a flame by smothering it and depriving it of oxygen).
But, unlike in a fire, which releases energy in an uncontrolled reaction, the energy, or life force, produced by mitochondria is stored in a chemical “battery,” a unique molecule called adenosine triphosphate (ATP). Energy-rich ATP can then be transported throughout the cell, releasing energy on demand in the presence of specific enzymes. 1
In addition to the fuel they produce, mitochondria also create a by-product related to oxygen called reactive oxygen species (ROS), also known as free radicals. 2
THE ROLE OF FREE RADICALS
These free radicals perform an important, positive function in human physiology. They play a pivotal part in regulating apoptosis , the process through which cells initiate self-destruction. Apoptosis happens when genetic switches that instruct a cell to die are turned on. While it may be puzzling to look upon cell death as a positive event, apoptosis is indeed a critical function that enables growth and healing of the greater organism.
Until quite recently, scientists pretty much subscribed to the paradigm that all cellular functions, including apoptosis, were directed by the cell nucleus. But, as Nick Lane notes in his compelling book, Power, Sex, Suicide, “there has been a change of emphasis that amounts to a revolution, overturning the nascent paradigm. The paradigm was that the nucleus is the operations centre of the cell, and controls its fate. In many respects this is of course true, but in the case of apoptosis it is not. Remarkably, cells lacking a nucleus can still commit apoptosis. The radical discovery was that the mitochondria control the fate of the cell: they determine whether a cell shall live or die.” 3 Mitochondria, then, must be looked upon as being so much more than simply organelles whose job involves turning fuel into energy. They wield the Sword of Damocles.
Hippocrates was the first to use the term apoptosis , which literally means “the falling of leaves from a tree.” However, apoptosis didn’t gain traction in the scientific community until the pathologist Alastair R. Currie published an important paper describing cellular self-destruction as a basic biological phenomenon. 4 Thereafter, researchers used apoptosis to describe the process through which the body intentionally eliminates cells in order to serve a larger purpose.
This process begins even while the fetus is in the womb. As an example, during embryonic development, human hands initially resemble the webbed appendages of a frog. But death of the cells in the webbed area transforms these extremities, allowing for definition of individual fingers and refinement of the entire hand.
Furthermore, after birth, apoptosis is the protocol that enables your body to continuously rid itself of as many as ten billion cells every day, making room for new, healthier cells. The outcasts include a multitude of cancer cells. Most of the time, when these pathogenic cells appear, mitochondria send a signal that tells them to die rather than replicate. This is a very important mitochondrial function because runaway
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