Biochemistry textbooks depict mitochondria as oxygen-dependent organelles, but many mitochondria can produce ATP without using any oxygen. In fact, several other types of mitochondria exist and they occur in highly diverse groups of eukaryotes - protists as well as metazoans - and possess an often overlooked diversity of pathways to deal with the electrons resulting from carbohydrate oxidation. These anaerobically functioning mitochondria produce ATP with the help of proton-pumping electron transport, but they do not need oxygen to do so. Recent advances in understanding of mitochondrial biochemistry provide many surprises and furthermore, give insights into the evolutionary history of ATP-producing organelles.
Bibliographical noteFunding Information:
We thank Paul Deley for preparing the figures. C.R. is the recipient of a Ph.D. stipend from the Studienstiftung des deutschen Volkes. Work in the laboratory of W.M. is supported by the Deutsche Forschungsgemeinschaft and Sonderforschungsbereich-Transregio 1. Work in the laboratory of A.G.M.T. and J.J.vH. is supported by The Netherlands Organization for Scientific Research: The Netherlands Foundation for Chemical Research, and the Life Science Foundation.