Thioglycolic acid corresponding disulfide (2-[(carboxymethyl)disulfanyl]acetic acid or dithiodiglycolic acid): Thioglycolic acid, usually as its dianion, forms complexes with metal ions. Such complexes have been used for the detection of iron, molybdenum, silver, and tin. Thioglycolic acid reacts with diethyl acetylmalonate to form acetylmercaptoacetic acid and diethyl malonate, the reducing agent in conversion of Fe(III) to Fe(II). Scientist David R. Goddard, in the early 1930s, identified TGA as a useful reagent for reducing the disulfide bonds in proteins, including keratin (hair protein), while studying why protease enzymes could not easily digest hair, nails, feathers, and such. He realized that while the disulfide bonds,
Hair (Lady Gaga song) about having a good time." Matthew Perpetua from "Rolling Stone" called it a mixture of yearning romantic melodrama of "We Belong" with the hard industrial metal edge of Broken-era Nine Inch Nails. Greg Kot of the "Chicago Tribune" felt that Gaga's vocals are Auto-Tuned throughout the song. The lyrics of "Hair" talk about embracing one's hairstyle as the ultimate expression of their identity, hence it ends with Gaga triumphantly declaring "I am my hair!" at the end of the final chorus. "Hair" has received mostly positive reviews. An hour before starting the final leg of The Monster Ball Tour, Gaga