Coenzyme Q10

Coenzyme Q (CoQ /ˌkoʊkjuː/), also known as ubiquinone, is a naturally occurring biochemical cofactor (coenzyme) and an antioxidant produced by the human body. The human body mainly produces the form known as coenzyme Q₁₀ (CoQ₁₀, ubidecarenone), but other forms exist. CoQ is used by and found in many organisms, including animals and bacteria. As a result, it can also be obtained from dietary sources, such as meat, fish, seed oils, vegetables, and dietary supplements.

CoQ plays a role in mitochondrial oxidative phosphorylation, aiding in the production of adenosine triphosphate (ATP), which is involved in energy transfer within cells. The structure of CoQ₁₀ consists of a benzoquinone moiety and an isoprenoid side chain, with the "10" referring to the number of isoprenyl chemical subunits in its tail.

Although a ubiquitous molecule in human tissues, CoQ₁₀ is not a dietary nutrient and does not have a recommended intake level, and its use as a supplement is not approved in the United States for any health or anti-disease effect.

CoQ₁₀ is a component of the mitochondrial electron transport chain (ETC), where it plays a role in oxidative phosphorylation, a process required for the biosynthesis of adenosine triphosphate, the primary energy source of cells.

CoQ₁₀ is a lipophilic molecule that is located in all biological membranes of human body and serves as a component for the synthesis of ATP and is a life-sustaining cofactor for the three complexes (complex I, complex II, and complex III) of the ETC in the mitochondria. CoQ₁₀ has a role in the transport of protons across lysosomal membranes to regulate pH in lysosome functions.

The mitochondrial oxidative phosphorylation process occurs in the inner mitochondrial membrane of eukaryotic cells. This membrane is highly folded into structures called cristae, which increase the surface area available for oxidative phosphorylation. CoQ₁₀ plays a role in this process as an essential cofactor of the ETC located in the inner mitochondrial membrane and serves the following functions:

Coenzymes Q is a coenzyme family that is ubiquitous in animals and many Pseudomonadota, a group of gram-negative bacteria. The fact that the coenzyme is ubiquitous gives the origin of its other name, ubiquinone. In humans, the most common form of coenzymes Q is coenzyme Q₁₀, also called CoQ₁₀ (/ˌkoʊkjuːˈtɛn/) or ubiquinone-10.

Coenzyme Q₁₀ is a 1,4-benzoquinone, in which "Q" refers to the quinone chemical group and "10" refers to the number of isoprenyl chemical subunits (shown enclosed in brackets in the diagram) in its tail. In natural ubiquinones, there are from six to ten subunits in the tail, with humans having a tail of 10 isoprene units (50 carbon atoms) connected to its benzoquinone "head".