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Unformatted text preview: alanine cycle •Vigorously working muscles operate nearly anaerobically and rely on glycolysis for energy •Glycolysis yields pyruvate that muscles cannot metabolize aerobically; if not eliminated lactic acid will build up •This pyruvate can be converted to alanine for transport into liver. •The pyruvate produced by deamination of Ala in the liver is converted to glucose and transported back to the muscle. 3 B. The urea cycle and related reactions
In mammals Aminotransferase NADP B. The urea cycle and related reactions
Aminotransferase α -keto acid keto acid Aspartate aa
Ornithine transcarbamoylase α-ketoglutarate
Aminotransferase α -keto acid keto acid glutamate Argininosuccinate Argininosuccinate synthase synthase Malate Arginase Arginine fumarase One of the amino group of urea comes from Carbamoyl phosphate, the other comes from Aspartate
Malate dehydrogenase 4 The Aspartate-argininosuccinate shunt
The urea cycle results in a net conversion of oxaloacetate to fumarate , both intermediates of the citirc acid cycle. Urea cycle and...
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