Ubiquinone
Sorry, this answer is incorrect. Ubiquinone is actually found in the membranes of the endoplasmic reticulum, lysosomes, vesicles, and the inner membrane of the mitochondrion. Ubiquinone has the ability to transfer electrons, such as in the electron transport chain of the mitochondrion, and acts as an antioxidant. This substance has recently become a fashionable dietary supplement. Ubiquinone is also known as Coenzyme Q.