4. Pepsin is the proteolytic enzyme of gastric juice.The active form of this enzyme is formed from properties of this enzyme.For this: pepsinogen under HCl, action Optimum of enzyme action: pH=1.5,t=37^circ Describe the 1) Name and explain the mechanism of this enzyme activation. 2) Draw the plot and explain the effects of pH and ton the reaction velocity. 3) Explain how changes the velocity of this reaction in patients suffering from hypoacidic gastritis.

1) The active form of pepsin is formed from pepsinogen through the action of hydrochloric acid (HCl) in the stomach. The mechanism of this activation involves the following steps:<br /><br />a) Pepsinogen is secreted by the chief cells in the stomach lining.<br />b) Pepsinogen is activated to pepsin by the action of HCl, which lowers the pH of the stomach to around 1.5.<br />c) The low pH causes a conformational change in the pepsinogen molecule, exposing the active site and allowing it to cleave itself to form pepsin.<br />d) Pepsin is a proteolytic enzyme, meaning it can break down other proteins into smaller peptides.<br /><br />2) The plot below shows the effect of pH and temperature on the reaction velocity of pepsin.<br /><br /><br /><br />The plot shows that pepsin has an optimum pH of 1.5 and an optimum temperature of 37°C. At these conditions, the reaction velocity is at its maximum. As the pH or temperature deviates from the optimum, the reaction velocity decreases.<br /><br />3) In patients suffering from hypoacidic gastritis, the stomach produces less HCl, resulting in a higher pH in the stomach. This can lead to a decrease in pepsin activity, as the pH is no longer optimal for pepsin activation. As a result, the velocity of the reaction catalyzed by pepsin may decrease, leading to reduced protein digestion in the stomach.