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.
The Roman Republic was gone. In its place, the government was now a dictatorship, under the leadership of an emperor. The first Roman emperor was Augustus, the adopted son of Julius Caesar. He was emperor for 45 years. This was the beginning of the Pax Romana or Roman Peace. This is a very misleading title. There wasn't really peace. Rome continued to expand the empire, mostly through conquest. Rome itself was still beset by criminals and sometimes riots. It is called the Pax Romana because the empire itself was stable. The people knew that there was an emperor to run things and Roman legions to take care of wars and riots. They didn't have to worry about somebody coming in and conquering Rome and destroying their beautiful city.