Mitochondrion Mitochondrion are the power plant of a cell. The mitochondria are cells based within a cell that turn nutrients from chemical form into a more simple and usable substance for a cell to use as energy. These sausage-shaped organelles are not a true organelle, but more of a parasite that invaded primordial cells and evolved along with them. A mitochondrian’s main purpose is to burn energy through a slow method of combustion, which will consume as much air to burn as fire will, just to break down nutrients into simpler substances. These simpler molecules then bond with the atoms that will need the energy to function. Then, enzymes in the mitochondrion break up t