Question

Which of the following principles is not true for zymogen activation?
(a)Liberation of activation molecules
(b)Hydrolysis of large inactive precursors
(c)Splitting off an inhibitor precursors
(d)Conformational change brings certain amino acid residues together.

Answer 1

The zymogen is inactive precursors of enzymes that undergo activation by proteolytic cleavage. It is cleaved to form the active enzyme. Zymogens can be activated by proteases that cut the amino acid bonds.

complete answer:
-Zymogens can also be activated by the environment and then they become autocatalytic.
-Autocatalysis is self-activation, and it happens when something in the environment allows the zymogen to cut its own chemical bonds.
-Activation of zymogens is catalyzed by proteolytic enzymes, which operate with a high degree of specificity and selectivity, affecting the hydrolysis of a limited number of peptide bonds in the zymogen molecule.

Additional information:
- Activation of zymogens is irreversible, and so proteolysis is stopped by a different mechanism.
-Specific cleavage causes conformational changes in the structure that exposes the enzyme active site.
-Proteolytic enzymes are inactivated by inhibitor proteins that bind very tightly to the enzyme active site.
-Zymogens are mainly secreted by the pancreas to prevent enzymes from digesting proteins in those cells in which they were formed.
-Zymogens are also produced by fungi as digestive enzymes into the environment.
-Enzymes like pepsin are first created in inactive form pepsinogen, an inactive zymogen that is later activated.
From the above data, it is clear that conformational change bringing amino acid residues together is not true for zymogen activation.

So, the correct answer is ‘Conformational change brings certain amino acid residues together’.

Note: Zymogens aid in enzyme folding, stability, and targeting. Biochemical change that activates a zymogen generally takes place in Golgi bodies. The zymogen that is inactivated and is called proenzyme.