The human body can synthesize non-essential amino acids through various metabolic pathways. Non-essential amino acids are those that can be produced by the body and are not required to be obtained through the diet. There are 11 non-essential amino acids: alanine, arginine, asparagine, aspartate, cysteine, glutamate, 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, forming alanine and -ketoglutarate.2. Arginine: Arginine is synthesized through the urea cycle, which involves several enzymes, including carbamoyl phosphate synthetase I, ornithine transcarbamylase, and argininosuccinate synthetase.3. Asparagine: Asparagine is synthesized from aspartate through the action of the enzyme asparagine synthetase, which transfers an amino group from glutamine to aspartate, forming asparagine and glutamate.4. Aspartate: Aspartate is synthesized from oxaloacetate through the action of the enzyme aspartate aminotransferase AST , which transfers an amino group from glutamate to oxaloacetate, forming aspartate and -ketoglutarate.5. Cysteine: Cysteine is synthesized from serine and homocysteine through the action of the enzyme cystathionine -synthase, which forms cystathionine. Cystathionine is then converted to cysteine by the enzyme cystathionine -lyase.6. Glutamate: Glutamate is synthesized from -ketoglutarate through the action of the enzyme glutamate dehydrogenase, which adds an amino group to -ketoglutarate, forming glutamate.7. Glutamine: Glutamine is synthesized from glutamate through the action of the enzyme glutamine synthetase, which adds an amino group to glutamate, forming glutamine.8. Glycine: Glycine is synthesized from serine through the action of the enzyme serine hydroxymethyltransferase, which removes a methyl group from serine, forming glycine.9. Proline: Proline is synthesized from glutamate through a series of enzymatic reactions involving the enzymes glutamate-5-semialdehyde dehydrogenase, pyrroline-5-carboxylate reductase, and proline dehydrogenase.10. Serine: Serine is synthesized from 3-phosphoglycerate through a series of enzymatic reactions involving the enzymes phosphoglycerate dehydrogenase, phosphoserine aminotransferase, and phosphoserine phosphatase.11. Tyrosine: Tyrosine is synthesized from phenylalanine through the action of the enzyme phenylalanine hydroxylase, which adds a hydroxyl group to phenylalanine, forming tyrosine.These biosynthesis pathways are interconnected and regulated to maintain the appropriate levels of amino acids in the body. The enzymes involved in these pathways are subject to regulation by various factors, including substrate availability, allosteric regulation, and covalent modification.