Substrate Cycling


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.