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 removal Justice, its highest governing body. Sikhs take an even stronger stance, opposing all forms of hair removal. One of the "Five Ks" of Sikhism is Kesh, meaning "hair". To Sikhs, the maintenance and management of long hair is a manifestation of one's piety. Under Muslim law (Sharia), it is recommended to keep (the beard), and that which is the object of recommendation (foot, hand, back, and chest hair). A Muslim may trim or cut hair on head. The hairs on the chest and the back may be removed. In the 9th century, the use of chemical depilatories for women was