The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.

DEFINITION:

cytochrome c oxidase

An enzyme complex of the inner mitochondrial membrane that catalyzes the transfer of electrons from cytochrome c to oxygen, oxidizing the former and reducing the latter in the final step of the electron transport chain by which oxygen is used for fuel combustion. The enzyme contains cytochromes a and a₃, and two copper atoms and is associated with proton translocation and the resultant synthesis of ATP. The Fe²⁺ in heme a has a strong affinity for CO; in the Fe³⁺ state it binds CN-, S^2-, and N₃. The binding of these compounds inactivates the enzyme, a cause of their extreme toxicity for all aerobic organisms. Called also cytochrome aa₃ and cytochrome oxidase.