The origin of mitochondria

http://www.carnitinaofficialsite.it/cms/index.php?option=com_content&view...

At the dawn of life, about 1 million years ago, unicellular organisms lived on earth. Despite the absence of oxygen they were able to produce enough energy to survive, in the form of ATP or adenosine triphosphate, a molecule containing three phosphorus ions linked with high energy bonds, known as the energy carrier par excellence.
They were, and still are, unable to use oxygen, but managed to obtain 2 ATPs for every mole of sugar, and they fed on bacteria by phagocytosis. One of them, the mitochondrion, developed a second outer membrane. As luck would have it, the first plant forms on the earth were beginning to produce oxygen in increasing quantities and cells could now use it to metabolise a variety of substances which had been partially or totally indigestible so far, in particular sugars and fats.
The mitochondrion not only could digest these substances, it could also obtain energy to store in precious ATP which it could then pass on to the cell in its entirety.
Thus, the situation of cells changed radically. They no longer had just enough energy to survive, but had so much that they could group together and specialize, exchanging information and services. Another phase of life on earth had started.
In its current form the mitochondrion is bean-shaped and about one micron or a thousandth of a millimetre long. Its genetic code is separate from that of its host cell.
This DNA has the unique characteristic of being very short, containing only 16,569 nucleotides, as compared to the 3 billion of the cell. Its only job is to codify the 13 proteins and related RNA, in other words, only those responsible for producing energy. Everything else concerning its maintenance is delegated to the DNA of the cell of which the mitochondrion had become an integral and indispensable part. The mitochondrial DNA does not reproduce in the same way as the cell, probably because it is too heavy to be transported on the already overcrowded sperm head into the egg cell. The new life that results will have only its maternal mitochondria.

Category:

Science & Technology

Tags:

• Carnitine
• energy
• metabolism
• amino
• acids
• mitochondria
• mitochondrion
• fat
• burn

[spotlightman1234]

At the dawn of life about 1 million years ago... umm eukaryotes originated about 2 billion years ago.

[h2rryp0tter]

are you French or something?

[vijayhinderboy]

cool