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
What Is the Fastest Thing in the World? What Is the Fastest Thing in the World? What Is the Fastest Thing in the World? is a Greek fairy tale collected by Georgios A. Megas in "Folktales of Greece". It is Aarne-Thompson type 875 and has many Greek and Slavic variants, generally revolving about the exchange of clever answers. This type of tale is the commonest European tale dealing with witty exchanges. In ballad form, the clever answers to the riddles, and the winning of a husband by them, are found in Child ballad 1, "Riddles Wisely Expounded". A brother argue over how they should split their land, some