In order to survive, the human body needs energy. This is obtained from food and then enters the cells via the blood. However, in order to be used or stored there, it must first be “burned” – much like gasoline in an engine. This is the job of the mitochondria, which are therefore also known as the body’s power plants.
Mitochondria – structure
Mitochondria are special small cell organs that are present in every cell – they are especially abundant in muscle, nerve, sensory and egg cells. A mitochondrion is usually bean-shaped, but occasionally round. It consists of an inner and an outer membrane.
While the outer membrane envelops the organelle like a shell, the inner membrane is folded and fanned out. Between these folds is the fluid mitochondrial matrix. The protein complexes of the respiratory chain contained therein are responsible for the actual energy production.
In addition, the matrix contains its own genome, the ring-shaped DNA of the mitochondrion, as well as ribosomes. The mitochondrial genome accounts for about one percent of human genetic information. Therefore, defective mitochondria can cause about 50 different diseases (mitochondriopathies).
Mitochondria – Function
Mitochondria arise from themselves by bacterial-like bipartition. Food that is taken into the body is first digested and then absorbed into the blood. There it is in turn distributed to the cells, where it is converted into storage energy by cellular respiration or oxidation.
Since the chemical functions of the respiratory chain take place in the mitochondria, the released energy is transformed there, stored in a molecule called adenosine triphosphate (ATP), and can thus be used at any time. Once mitochondria are used up, they are broken down by the endoplasmic reticulum, the Golgi apparatus, and lysosomes.
