The cheapest way to produce a high yield of it is by hydrolysis of human hair due to the 25% content of this substance in keratin, which has led some to wonder whether doing so constitutes cannibalism.  One of the five amino acids that is broken down to pyruvate, it is one of three amino acids synthesized in the body from 3-phosphoglycerine through serine. A strong nucleophile, it is highly reactive at cellular pH, and thus is critical for production of the antioxidant glutathione. The only amino acid that can create a 
The cheapest way to produce a high yield of it is by hydrolysis of human hair due to the 25% content of this substance in keratin, which has led some to wonder whether doing so constitutes cannibalism.  One of the five amino acids that is broken down to pyruvate, it is one of three amino acids synthesized in the body from 3-phosphoglycerine through serine. A strong nucleophile, it is highly reactive at cellular pH, and thus is critical for production of the antioxidant glutathione. The only amino acid that can create a disulfide bond, FTP, name this amino acid characterized by its thiol group, symbolized by the letter C.
The cheapest way to produce a high yield of it is by hydrolysis of human hair due to the 25% content of this substance in keratin, which has led some to wonder whether doing so constitutes cannibalism.  
cysteine (prompt on "C")