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.
Some simple cells contain only one or two mitochondria. However, complex animal cells that need a lot of energy, like muscle cells, can have thousands of mitochondria. Energy Factory The main function of mitochondria is to produce energy for the cell. Cells use a special molecule for energy called ATP. ATP stands for adenosine triphosphate. The ATP for the cell is made within the mitochondria. You can think of the mitochondria as the energy factory or power plant of the cell. Respiration Mitochondria produce energy through the process of cellular respiration. Respiration is another word for breathing.