ABSTRACT
In mammalians, triacylglycerols are located essentially in the cytoplasm of adipocytes. One can say that adipocytes are specialized in the synthesis and in the “stockage” of triacylglycerols and in their “mobilisation” as molecules of fuel which are brought to other “tissues” by blood. Amino-acids, in excess relatively to those necessary for the synthesis of proteins and other biomolecules, cannot be stocked on the contrary to fatty acids and glucose and can no longer be excreted. The excess of amino-acids is used as fuel. In the metabolism, the rest amino acid is removed from the carbon bone and the latter becomes an important metabolic intermediary. Briefly, one of the nitrogen atoms of urea comes from the amino acid aspartate. The fumarate is hydrated in malate which is itself oxidized in oxaloacetate. One knows the different pathways in which the oxaloacetate (transamination in aspartate, conversion in glucose-neoglucogenesis, condensation with acetyl CoA, conversion in pyruvate) participates.
