Substrate Cycling
Synonyms
Cycle, Futile
Cycle, Futile Substrate
Cycles, Futile
Cycles, Futile Substrate
Cycling, Futile
Cycling, Futile Substrate
Cycling, Substrate
Cyclings, Futile
Cyclings, Futile Substrate
Cyclings, Substrate
Futile Cycle
Futile Cycles
Futile Cycling
Futile Cyclings
Futile Substrate Cycle
Futile Substrate Cycles
Futile Substrate Cycling
Futile Substrate Cyclings
Substrate Cycle, Futile
Substrate Cycles, Futile
Substrate Cycling, Futile
Substrate Cyclings
Substrate Cyclings, Futile
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.