Metabolism and Energy Transformation in Body Cells - Renata Armenakovna Petrosova 2004

Enzymatic nature of metabolic reactions

Every Cell—whether animal, plant, or bacterial, highly complex or very primitive—is characterized by intricate chemical processes. A vital feature of the Chemical Reactions taking place within a cell is their catalytic nature. The biological catalysts involved are specialized Proteins known as Enzymes.

Hundreds of metabolic reactions occurring within The Cell proceed with the direct participation of enzymes. The substance that binds to an enzyme to undergo a chemical reaction is called a substrate. Enzymes activate the substrate, making it susceptible to the reaction. While accelerating chemical reactions, these substances are not consumed in the process, nor do they affect The Nature of the end products.

Due to the high reaction rate, a small amount of enzyme can catalyze The conversion of a large quantity of substance, since the enzyme is released again very rapidly after each cycle.

Let us compare the reaction rates of inorganic catalysts and enzymes. To hydrolyze a protein into Amino Acids under laboratory conditions, it is necessary to boil the protein with a 20% Hydrochloric acid solution for 10–15 hours. However, if a few drops of the enzyme Trypsin or Chymotrypsin are added to the protein at room Temperature, the Hydrolysis is completed within 60–80 minutes. Comparing the conditions of these two reactions, we see that the enzyme operates under mild conditions while its reaction rate vastly exceeds that of inorganic catalysts.