The tricarboxylic acid cycle in fish

Abstract The enzymes of the tricarboxylic acid (TCA) cycle have been demonstrated in fish tissue homogenates or mitochondrial preparations. Carp liver mitochondria catalyze the oxidation of TCA intermediates and glutamate accompanied by coupled phosphorylation of adenosine diphosphate. Phosphate esterification approached the theoretical maximum of the electron-transport system of mammals. The degree of respiratory control in fish mitochondrial preparations was found to be similar to that reported for rat liver mitochondria. Cytochromes and flavoprotein components of fish mitochondria were identified by by means of difference spectra and found to be strikingly similar to those of higher mammals.