Amino acid pool

·        It is the free amino acid content distributed throughout the extracellular fluid.

·        Quantitatively it is about 100g in an adult individual of which glutamate and glutamine together represent 50% essential amino acids represent 10% and other amino acid represent 40%.

·        Amino acid pool is always being reestablished by amino acid coming from three sources

o   Dietary protein

o   Endogenous amino acid synthesis

o   Endogenous protein breakdown.

·        Amino acid pool is constantly undergoing depletion due to disposal of amino acid through different metabolic processes usually at a rate equal to the rate by which amino acid feed the pool.

·        Metabolic fates experienced by the amino acids of amino acid pool are:

o   Synthesis of tissue protein

o   Synthesis of non protein nitrogenous substances

o   Transamination and deamination leading to generation of NH₃ and carbon skeleton of amino acid.

o   NH₃ is converted to urea and carbon skeleton may be oxidized or utilized for synthesis of glucose, acetyl CoA, fatty acid, Ketone bodies, Steroids.