Which of the following statements regarding pepsin is FALSE?
Pepsin is derived from the inactive enzyme pepsinogen
Pepsin primarily works to digest fatty acids
Pepsinogen secretion is stimulated by increased protein concentration, gastric distension, and the sight/smell/taste of food
Pepsinogen is converted to pepsin in the presence of a high concentration of H+ ions as well as the presence of pepsin itself
To determine which statement regarding pepsin is false, let's examine each statement:
1. "Pepsin is derived from the inactive enzyme pepsinogen."
This statement is true. Pepsin is derived from the inactive precursor enzyme called pepsinogen, which is secreted by the gastric chief cells in the stomach. Pepsinogen is converted to pepsin when it encounters the acidic environment of the stomach.
2. "Pepsin primarily works to digest fatty acids."
This statement is false. Pepsin primarily works to digest proteins, not fatty acids. It breaks down protein molecules into smaller peptides for further digestion in the small intestine.
3. "Pepsinogen secretion is stimulated by increased protein concentration, gastric distension, and the sight/smell/taste of food."
This statement is true. Pepsinogen secretion is stimulated by increased protein concentration in the stomach, gastric distension (stretching of the stomach), and the sight, smell, or taste of food. These factors signal the stomach to release pepsinogen in preparation for protein digestion.
4. "Pepsinogen is converted to pepsin in the presence of a high concentration of H+ ions as well as the presence of pepsin itself."
This statement is true. Pepsinogen is converted to pepsin in the presence of a high concentration of H+ ions (acidic environment of the stomach) and the presence of pepsin itself. Once pepsinogen is partially activated by the acidic environment, it can further activate other pepsinogen molecules, resulting in the conversion of more pepsinogen to pepsin.
Therefore, the false statement regarding pepsin is: "Pepsin primarily works to digest fatty acids."