In enzymes, some of these amino acids form a site in the structure that catalyzes the enzymatic reaction. This site, called the active site of the enzyme, has amino acids that bind specifically to the substrate molecule, also called a ligand (Fig. 2). In a similar manner, certain sites in cell receptor proteins bind to specific ligand molecules that the receptor recognizes.
When did France's second empire end? The Second Empire ended with the swift and catastrophic defeat of  France in the Franco-Prussian war of 1870. The war was engineered  by Bismarck with the idea that Germany â¦would be united.This  included the capture by the Prussians of the Napoleon III. Then the  proclamation at Versailles of the German Empire, the loss to France  of Alsace and Lorraine, and the proclamation of the Third Republic.
Three Kingdoms Period. Just as the name implies, the Three Kingdoms were made up of three kingdoms - Wei, Shu and Wu. As a single dynasty, the Three Kingdoms Period originated in 220 AD when Wei replaced the Eastern Han Dynasty (25 AD-220 AD) and ended in 280 AD when the Wu was defeated by the Court of Jin.