Mitochondria ?
Energy factories of cells
True microscopic organs, mitochondria provide the basic energy necessary for an organism to function.
Altered by the aging process, they are involved in the most well-known illnesses of the 21st century, such as the degenerative Alzheimer’s and Parkinson’s diseases…
Mitochondria represent, therefore, both a legacy to preserve and a multitude of potential therapeutic targets.
It is therefore probable that mitochondriology will, in the next several years, become a lead discipline in itself.
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Mitochondria produce ATP energy molecules via the oxidation of nutritive substances.
Pyruvate comes from glycolysis and is transformed into acetyl CoA via oxidative decarboxylation.
Free fatty acids, activated in acyl-CoA in the external membrane and transported across the internal membrane by L-carnitine for long chains, are transformed into acetyl CoA via oxidation B.
Acetyl CoA is used during the Tricarboxylic Acid Cycle.
Certain amino acids such as leucine are transformed into acetyl CoA; others, like valine, are transformed into intermediary products for the Tricarboxylic Acid Cycle.
These enzymatic reactions that take place in the mitochondrial matrix cause the formation of NADH and FADH2 molecules.
The respiratory chain is composed of five proteic complexes located in the internal membrane.
NADH and FADH2 molecules are respectively oxidized during complex I and complex II. Electrons are then transferred from complex I or II to complex III and IV until they reach the final recipient, molecular oxygen.
The gradient of protons that is created generates a proto-motor force that allows the production of ATP during ATP synthetasis (complex V).
The bond between oxidations and phosphorylations is not 100% effective. Part of the oxygen consumed serves in the production of free radicals.