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
History of removal of leg and underarm hair in the United States American women aged 15–44 routinely shaved their legs. A century after these ad campaigns started, removal of leg and underarm hair by women in the U.S. is tremendously pervasive and lack of its removal is taboo. An estimated 80%-99% of American women today remove hair from their bodies. Celebrity unshaven armpit appearances started to make headlines. For example, this was the case with actress Julia Roberts who sported unshaven underarms at the Notting Hill movie premiere in 1999. Anne Robinson, a presenter British television show The Weakest Link, received a similar reaction after she revealed underarm hair on air in