Its architects didn't read The Art of War or Leadership Secrets of Attila the Hun . The origins of mitochondria When those ancient bacteria invaded primitive eukaryotic cells , they found a hospitable, protected environment with a ready supply of nutrients. In return, they provided an energy source for aerobic metabolism. The descendants of these archaebacteria are known today as mitochondria, and in plants, as chloroplasts. That's the theory scientists have put together from a variety of clues and suggestive inferences, and it helps makes sense of some otherwise inexplicable facts of molecular biology.
Mitochondria synthesize protein using biochemical pathways similar to prokaryotes.
Besides being a fascinating detective story in its own right, confronting the existence of mitochondria poses a somewhat embarrassing challenge to the complacent nucleus -centric view of the eukaryotic cell. Unveiled to great fanfare by the Scottish scientist Ian Wilmut, Dolly was presented as mammalian Xerox of her mother. But with all due respect to Dr. Wilmut, it just ain't so, wrote Dr. Walter Moos in Pharmaceutical News magazine earlier this year. Wilmut took a nucleus from a sheep's mammary gland cell and inserted it into an ovum from which the nucleus had been removed. That ovum, of course, contained its own mitochondria, combined with nuclear DNA from another sheep.