Mitochondrial refers to anything related to mitochondria, which are small, membrane-bound structures found in the cells of most living organisms. Often called the "powerhouses" of the cell, mitochondria are responsible for producing energy in the form of adenosine triphosphate (ATP) through a process called cellular respiration. This energy is essential for various cellular functions and overall metabolism. Mitochondria have their own DNA, distinct from the nuclear DNA found in the cell's nucleus. This unique genetic material is inherited maternally, meaning it is passed down from mother to offspring. Mitochondrial dysfunction can lead to various health issues, including mitochondrial diseases, which can affect energy production and result in a range of symptoms.