Coenzyme Q, is a fat-soluble quinone compound existing in nature, whose structure is similar to vitamin K, vitamin E and plastiquinone. It is involved in energy production and activation in cells of the human body, and is the most effective antioxidant in preventing arteriosclerosis formation. Ubiquinone molecules contain a side chain composed of multiple isoprene units connected to the parbenzoquinone parent nucleus. The length of the side chain varies according to the source of ubiquinone, generally containing N =6 -- 10 isoprene units. In mammals, n=10, so it is also known as coenzyme Q10. The quinone structure in the molecule gives ubiquinones two forms, oxidized (ubiquinone) and reduced (ubiquinol). The two forms can be converted to each other in the cell, which is the basis of ubiquinone as an electron transporter. Ubiquinone electrons can be gained and lost in two steps, one electron at a time, or two electrons can be transferred simultaneously in one step. Ubiquinones are found in most eukaryotic cells, especially mitochondria. It is a component of the respiratory chain; Its content in the inner membrane of mitochondria is much higher than that of other components of respiratory chain, and its lipid solubility makes it highly mobile in the inner membrane, so it is especially suitable as a mobile electron transporter. The benzoquinone part of ubiquinone is synthesized in vivo from tyrosine, while the isoprene side chain is synthesized from acetyl CoA via mevalonate.