When a cell’s need for energy production increases, a mitochondria can simply
pinch into two. The two halves increase in size, thereby increasing the ability to
produce ATP. The dependence of cells on the energy provided by mitochondrial
oxidative metabolism of glucose, especially through critical organs such as the
heart and brain, is underlined by the fatal consequences when toxins interfere
with the mitochondrial electron transport system. If the mitochondrial theory of
aging is correct, then the root cause of aging is damage to mitochondrial DNA by
free radical leakage from adjacent cellular-respiratory proteins. The high oxidant
exposure of mitochondrial DNA, and its poor ability to repair itself are thought
to make it most susceptible to such accumulated damage. Mitochondrial damage
would then lead to a loss of energy, reducing the nutrition and detoxification of
the cell.
There are three interlinked energy production cycles:
- The glycolytic (sugar burning).
- The Krebs’ citric acid cycles
(aminos and fats are “burned” through the Krebs’ cycle). - The electron transport side chain.
The electron “sparks” released from the step by step slow “burning” that
occurs in the Krebs’ cycle provide the fuel used by the electron transport side
chain to generate much of the ATP bioenergy that literally powers our life. Heat
is produced in all animals by the breakdown of ATP and as a by-product of other
biochemical reactions. In brown fat cells, a special protein called uncoupling
protein is produced. This protein disrupts the creation of the proton gradient by
making the inner mitochondrial membrane “leaky.” As a result, the cells make less
ATP and release more energy in the form of heat. Similar uncoupling proteins
are found in skeletal muscle. In this way brown adipose tissue and skeletal muscle
produces abundant heat by uncoupling the production of ATP from the electron
transport chain.
Any food not utilized for energy is subsequently stored for use later, and mostly
as fat since it is the most efficient energy storage form at 9 kcal/gm. ATP, while
a good energy packet, is not a good fuel storage molecule, as it is used quickly
after being formed. Better storage forms of energy are glycogen and triglycerides.
Glycogen is broken down to glucose and triglycerides are broken down to fatty
acids, both of which are readily utilized for energy. The synthesis of triglycerides
requires glycerol (from carbohydrates), fatty acids and energy from ATP. Co-
enzyme A, derived from pantothenic acid (B5) activates the fatty acids and
glucose in the Krebs Cycle performed within the mitochondria. The Krebs cycle is
a system of removing H 2 from foodstuffs which are then combusted to water and
the free energy obtained is used to form the higher energy compound ATP.
oxidative phosphorylation: In the inner membrane of the mitochondria
are large molecules capable of rapidly alternating oxidation and reduction...the
electron transport system. Mitochondria take in small organic molecules-like
pyruvate (formed by the partial breakdown of sugars) or fatty acids (formed by
the partial breakdown of fats) and break them down. acetyl coa, an essential