Futile Cycling

《英文msh詞典》Futile Cycling
[同義詞] Futile Cycling
[主題詞] Substrate Cycling
[中文釋義] 無效循環
[英文釋義] A set of opposing,nonequilibrium reactions catalyzed by different enzymes which act simultaneously,with at least one of the reactions driven by ATP hydrolysis. The results of the cycle are that ATP energy is depleted,heat is produced and no net substrate-to-product conversion is achieved. Examples of substrate cycling are cycling of gluconeogenesis and glycolysis pathways and cycling of the triglycerides and fatty acid pathways. Rates of substrate cycling may be increased many-fold in association with hypermetabolic states resulting from severe burns,cold exposure,hyperthyroidism,or acute exercise.