mitokondríum

The mitochondrion is a membrane-bound organelle found in eukaryotic cells. Often referred to as the "powerhouse" of the cell, its primary function is to generate most of the cell's supply of adenosine triphosphate (ATP), used as a source of chemical energy. This process is known as cellular respiration. Mitochondria are unique in that they possess their own DNA, separate from the nuclear DNA of the cell. This mitochondrial DNA (mtDNA) is typically inherited maternally.

Structurally, a mitochondrion is enclosed by two membranes: an outer membrane and an inner membrane. The inner membrane is folded into cristae, which increase the surface area for ATP synthesis. The space enclosed by the inner membrane is called the mitochondrial matrix, which contains enzymes, ribosomes, and mtDNA. Besides energy production, mitochondria play roles in other cellular processes, including cell signaling, cell differentiation, cell death (apoptosis), and the regulation of the cell cycle and cell growth. Their importance is highlighted by their presence in virtually all eukaryotic cells. Defects in mitochondrial function are linked to a variety of human diseases.