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.
It is bounded by two sets of membranes, a smooth outer one and an inner one that is arranged in folds, or cristae, that extend into the interior of the mitochondrion, called the matrix. Mitochondria provide the principal source of cellular energy through oxidative phosphorylation and adenosine triphosphate synthesis. They also contain the enzymes involved with electron transport and the citric acid and fatty acid cycles.
A: Mitochondria are the membrane-bound structures that produce energy for cells. The mitochondria are thought to be descended from a once free-living cell that set up a symbiotic relationship with a host cell. Mitochondria are organelles, membrane-bound structures that perform specific functions within a cell.