Split reins are a piece of equipment used for communicating with a horse while it is being ridden. Split reins are actually two separate, individual reins that are used together, with one rein on each side of the horse's neck.
As discussed above, mitochondria are the sites of respiration, and generate chemical energy in the form of ATP by metabolizing sugars, fats, and other chemical fuels with the assistance of molecular oxygen.
The purpose of this breakdown is to produce as much ATP as possible through the process of glycolysis and the citric acid cycle. The ATP is then used to fuel other processes occurring in the rest of the cell. The mitochondrion is a unique organelle as it has its own variant of DNA. This allows the organelle to produce its own proteins, tRNAs and rRNAs.