High Protein Diets: No Storage of Amino Acids

This source explains that unlike other nutrients, amino acids contain nitrogen, which poses a unique challenge during metabolic breakdown. Because the body cannot store surplus amino acids as it does with fats or sugars, it must either use them for protein synthesis or dismantle them for energy. When these molecules are broken down, the nitrogen is converted into ammonia, a toxic byproduct that requires the urea cycle for safe elimination. The remaining carbon skeletons are repurposed for energy production. Ultimately, the carbon skeletons are converted to either glucose or acetyl CoA. The latter two molecules are oxidized to CO2 to produce energy.