Inactive enzyme precursors such as pepsinogen for pepsin are called as:

Explanation

Inactive enzyme precursors like pepsinogen for pepsin are commonly referred to as "zymogens" or "proenzymes." Zymogens are inactive forms of enzymes that need to undergo a specific biochemical change to become active. This transformation usually involves the removal of a peptide segment or another modification that exposes the active site of the enzyme, allowing it to catalyze reactions. In the case of pepsinogen: Pepsinogen is the inactive precursor. Pepsin is the active form of the enzyme. The conversion of pepsinogen to pepsin occurs in the acidic environment of the stomach, where the acidic conditions lead to the cleavage of a portion of the pepsinogen molecule, resulting in the activation of pepsin. Zymogens are a safety mechanism in the body to prevent the premature activation of enzymes and potential damage to tissues. They are activated at the right time and place, ensuring that enzymatic activities are tightly regulated.