It is difficult to give one specific individual the credit for who discovered mitochondria. The entire course of development from the initial sighting to the eventual classification of the so-called power plant of the cell had a slow but steady progress, spanning over a century of research conducted by a succession of brilliant scientific minds.
The history of mitochondria’s discovery began in 1857, when Swiss anatomist and physiologist Albert von Kolliker revealed the presence of granule-like structures in muscle cells. Kolliker’s claim was substantiated by other scientists at the time who had observed that the granules also appeared in other cell types. Then in 1886, a cytologist named Richard Altman employed a dye technique to identify the granules. Terming them “bioblasts,” Altman hypothesized that these organelles were the basic units of cell activity. It would be in 1898 that Carl Benda would rename the bioblast as “mitochondria,” taken from the Greek words “mitos” (thread) and “chondros” (granules).
But the story behind who discovered mitochondria does not end with the breakthroughs of Kolliker, Altman and Benda. In the succeeding decades, many more would make their own discoveries on the properties and functions of the mitochondrion. Among these was Berman biochemist Otto Heinrich Warburg, who postulated in 1912 that an enzyme found inside cells facilitated processing of oxygen, and that respiration can be affected by cyanide on a cellular level. Entomologist David Keilin conducted an experiment in 1923 to illustrate how, during respiration, a change occurs in the oxidation state within a cytochrome (a hemoprotein in charge of carrying out electron transport). Keilin would later discover the presence of cytochrome c, a part of the mitochondria’s inner membrane.
In 1929, C.H. Fiske and Y. Subbarow were able to isolate ATP or Adrenosine Triphosphate, which is responsible for transporting chemical energy within the cell. A separate research conducted by H.M. Kalckar and V.A. Belitser would demonstrate oxidative phosphorylation, a process wherein cellular respiration is aided by adding phosphate to protein.
Harvesting the mitochondria from liver would greatly aid the scientists who discovered mitochondria’s different functions. In 1950, Eugene Kennedy and Albert Lehninger were able to prove the occurrence of oxidation within the organelles. Later, Nobel Prize-winning British biochemist Peter D. Mitchell proposed the theory of chemiosmotics, which explained how the ions of hydrogen dispersed across cell membranes and how it is related to ATP when respiration occurs in eukaryotic cells. Introduced in 1978, this theory played a significant part in establishing the mitochondria’s general function, which is breaking down food molecules such as carbohydrates and sugar and converting them into ATP molecules that store the energy necessary for the cell to perform its metabolic functions. Then in 1997, Professor Paul Boyer won the Nobel Prize for discovering the role of mitochondria in the combination of adenosine diphosphate and inorganic phosphate to produce ATP.
It took decades, literally a century and a half, before the secrets of the thread-like granules in the cell were finally unlocked. This was not due to the efforts of but one man, but of a long line of researchers who discovered mitochondria as a scientific puzzle to be pieced together. It’s something of a wonder to note that an astronomical amount of time was spent in studying such a microscopic yet nonetheless important component of the human body.