Aerobic Respiration—Chemoorganotrophic Bacteria
1975; Elsevier BV; Linguagem: Inglês
10.1016/b978-0-12-219352-1.50011-6
Autores Tópico(s)Microbial metabolism and enzyme function
ResumoThis chapter explains aerobic respiration of chemoorganotrophic bacteria. A great number of microorganisms and other living cells meet their energy needs with the oxidation of organic compounds by molecular oxygen and liberation of free energy. Appropriate groups of enzymes catalyze a series of consecutive transformations, including dehydrogenations, of these substrates, resulting in their complete oxidation to carbon dioxide and water. The electrons removed from the substrates during these oxidations flow through an organized arrangement of electron carriers from the lowest to the highest potential and finally to oxygen. In the course of this energy flow, ATP is generated and becomes available for biosynthesis. The aerobic breakdown of pyruvate carried out by the multienzyme system is inducible and pyruvate appears to be the metabolite causing this induction. In oxidation of pyruvate via the tricarboxylic acid cycle, pyruvate is completely broken down to carbon dioxide and water. The tricarboxylic acid cycle primarily concerns the fate of the carbon skeleton of acetic acid and is not involved in energy conservation. The growth of microorganisms on C2 compounds as the sole source of carbon necessitates reactions whereby the C2 substrates provide both metabolic energy and the carbon skeleton for cellular constituents.
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