Which amino acid from following is NOT synthesized in our body?

Step-by-step solution

Non-essential amino acids are synthesized by the human body, while essential amino acids must be obtained through diet. Tyrosine is non-essential, synthesized from phenylalanine. Glycine is non-essential, synthesized from serine. Glutamine is non-essential, synthesized from glutamate and ammonia. Tryptophan cannot be synthesized and is essential. Tryptophan is the amino acid not synthesized in the body.