The human body can synthesize non-essential amino acids through various metabolic pathways. Non-essential amino acids are those that the body can produce on its own, and they are not required to be obtained through the diet. There are 11 non-essential amino acids: alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.The synthesis of non-essential amino acids involves several key enzymes and metabolic pathways. Here are some examples:1. Alanine: Alanine is synthesized from pyruvate through the action of the enzyme alanine aminotransferase ALT , which transfers an amino group from glutamate to pyruvate.2. Arginine: Arginine is synthesized through the urea cycle, which involves a series of enzymatic reactions. Key enzymes include carbamoyl phosphate synthetase I, ornithine transcarbamylase, and argininosuccinate synthetase.3. Asparagine: Asparagine is synthesized from aspartic acid through the action of the enzyme asparagine synthetase, which transfers an amino group from glutamine to aspartic acid.4. Aspartic acid: Aspartic acid is synthesized from oxaloacetate through the action of the enzyme aspartate aminotransferase AST , which transfers an amino group from glutamate to oxaloacetate.5. Cysteine: Cysteine is synthesized from serine and homocysteine through the action of the enzyme cystathionine -synthase, which forms cystathionine, which is then converted to cysteine by the enzyme cystathionine -lyase.6. Glutamic acid: Glutamic acid is synthesized from -ketoglutarate through the action of the enzyme glutamate dehydrogenase, which adds an amino group to -ketoglutarate.7. Glutamine: Glutamine is synthesized from glutamic acid through the action of the enzyme glutamine synthetase, which adds an amino group from ammonia to glutamic acid.8. Glycine: Glycine is synthesized from serine through the action of the enzyme serine hydroxymethyltransferase, which transfers a methyl group from serine to tetrahydrofolate, forming glycine and 5,10-methylene tetrahydrofolate.9. Proline: Proline is synthesized from glutamic acid through the action of the enzyme glutamate 5-kinase, which phosphorylates glutamic acid, followed by the action of the enzyme pyrroline-5-carboxylate reductase, which reduces the intermediate pyrroline-5-carboxylate to proline.10. Serine: Serine is synthesized from 3-phosphoglycerate through the action of the enzyme phosphoglycerate dehydrogenase, which forms 3-phosphohydroxypyruvate, followed by the action of the enzyme phosphoserine aminotransferase, which transfers an amino group from glutamate to 3-phosphohydroxypyruvate, forming phosphoserine. Phosphoserine is then dephosphorylated by the enzyme phosphoserine phosphatase to form serine.11. Tyrosine: Tyrosine is synthesized from phenylalanine through the action of the enzyme phenylalanine hydroxylase, which hydroxylates phenylalanine to form tyrosine.These metabolic pathways and enzymes allow the body to synthesize non-essential amino acids, ensuring that the body has the necessary building blocks for protein synthesis and other vital cellular functions.