Protein or the physical region of the protein that participates in chemical catalysis. In solution proteins also undergo variation in structure through thermal vibration and the collision with other molecules. Proteins can be informally divided into three main classes, which correlate with typical tertiary structures: globular proteins, fibrous proteins, and membrane proteins. Almost all globular proteins are soluble and many are enzymes. Fibrous proteins are often structural, such as collagen, the major component of connective tissue, or keratin, the protein component of hair and nails. Membrane proteins often serve as receptors or provide channels for polar or charged molecules to pass
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