Coenzyme Q10, also known as ubiquinone, ubidecarenone, coenzyme Q, and abbreviated at times to 
CoQ10 /ˌkoʊ ˌkjuː ˈtɛn/, CoQ, Q10, or Q, is a 1,4-benzoquinone, where Q refers to the quinone chemical group, and 10 refers to the number of isoprenyl chemical subunits in its tail.
This oil-soluble, vitamin-like substance is present in most eukaryotic cells, primarily in the mitochondria. It is a component of the electron transport chain and participates in aerobic cellular respiration, generating energy in the form of ATP. Ninety-five percent of the human body’s energy is generated this way.[1][2] Therefore, those organs with the highest energy requirements—such as the heart, liver and kidney —have the highest CoQ10 concentrations.[3][4][5] There are three redox states of coenzyme Q10: fully oxidized (ubiquinone), semiquinone (ubisemiquinone), and fully reduced (ubiquinol). The capacity of this molecule to exist in a completely oxidized form and a completely reduced form enables it to perform its functions in electron transport chain and as an antioxidant respectively.
Coenzyme Q10 was first discovered by Professor Fredrick L. Crane and colleagues at the University of Wisconsin–Madison Enzyme Institute in 1957.[6][7] In 1958, its chemical structure was reported by Dr. Karl Folkers and coworkers at Merck; in 1968, Folkers became a Professor in the Chemistry Department at the University of Texas at Austin.[7][8] In 1961 Peter Mitchel proposed the electron transport chain (which includes the vital protonmotive role of CoQ10) and he received a Nobel prize for the same in 1978. In 1972, Gian Paolo Littarru and Karl Folkers separately demonstrated a deficiency of CoQ10 in human heart disease. The 1980s witnessed a steep rise in the number of clinical trials due to the availability of large quantities of pure CoQ10 and methods to measure plasma and blood CoQ10 concentrations. The antioxidant role of the molecule as a free radical scavenger was widely studied by Lars Ernster. Numerous scientists around the globe started studies on this molecule since then in relation to various diseases including cardiovascular diseases and cancer.