The cage is non-uniform. In its cytoplasm there are various organelles, each of which performs the function. Their work also provides normal cell activity, and behind it and all organism. One of the major organelles are mitochondrions.
Mitochondrions are tiny two-membrane organelles in the form of thread or a granule, characteristic of the vast majority of eukaryotic cells. The main function of mitochondrions are an oxidation of organic compounds and production of ATP molecules from the released energy. The small mitochondrion is the main power station of all organism.
Origin of mitochondrions
Among scientists the opinion is very popular today that the mitochondrion appeared in a cage not independently during evolution. Most likely, it happened because of capture by the primitive cage not capable at that time independently to use oxygen, bacteria which was able to do it and, respectively, was an excellent power source. Similar symbiosis was successful and was fixed in the subsequent generations. In favor of this theory specifies existence in mitochondrions of own DNA.
As mitochondrions are arranged
The mitochondrion possesses two membranes: external and internal. The main function of an external membrane is a separation of an organelle from cage cytoplasm. It consists of the bilipidny layer and proteins penetrating it through which transport of the molecules and ions necessary for a mitochondrion for work is carried out. While the external membrane smooth, internal forms numerous folds – Christa which significantly increase its area. The internal membrane mostly consists of proteins among which there are enzymes of a respiratory chain, transport proteins and large ATF-sintetaznye complexes. In this place there is an ATP synthesis. Between an external and internal membrane there is an intermembrane space with enzymes inherent in it. The internal space of mitochondrions is called matrix. Here the fermental systems of oxidation of fatty acids and pyruvate, enzymes of a cycle of Krebs and also hereditary material of mitochondrions – DNA, RNA and the beloksinteziruyushchy device are located.
For what mitochondrions are necessary
The main function of mitochondrions is synthesis of a universal form of chemical energy – ATP. Also they take part in a cycle of tricarboxylic acids, turning pyruvate and fatty acids into acetyl-CoA, and then oxidizing it. In this organelle the mitochondrial DNA coding reproduction of tRNK, rRNK and some proteins necessary for normal functioning of mitochondrions is stored and descended.