Exercise citric acid cycle during

Figure 17.21 PATHWAY INTEGRATION Pathways active during exercise after a nights rest. The rate of the citric acid cycle increases during exercise, requiring the replenishment of oxaloacetate and acetyl CoA. Oxaloacetate is replenished by its formation from pyruvate. Acetyl CoA may be produced from the metabolism of both pyruvate and fatty acids.

The overall pathway has a AG° of —77.7 y mol . During the course of the cycle, starting from pyruvate, four NADH molecules and one FADHg are produced. Between the GTP formed directly and the reoxidation of the reduced electron carriers by the electron transport chain, the citric acid cycle produces 25 ATP. Gontrol of the citric acid cycle is exercised at three points. 

Aragon, J.J., and J.M. Lowenstein. 1980. The purine nucleotide cycle. Comparison of the levels of citric acid intermediates with the operation of the purine nucleotide cycle in rat skeletal muscle during exercise and recovery from exercise. Eur. J. Biochem. 110 371-377. 

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