Which of the following reaction is catalyzed by Lyase?

Breaking of bonds

The correct answer is option 3. Breaking of bonds.

Lyases are a class of enzymes known for their ability to cleave (break) chemical bonds within a substrate molecule. They achieve this through a process called elimination, which involves the removal of a group from the substrate, often forming a double bond in the remaining molecule.

Unlike other enzyme classes like hydrolases (which use water to break bonds) or oxidoreductases (involved in electron transfer reactions), lyases typically don't involve hydrolysis or oxidation in their catalytic mechanisms.

The other options don't accurately represent Lyase activity:

1. Transfer of group from one molecule to another: This is more characteristic of transferase enzymes, which move functional groups between molecules.

2.Intramolecular rearrangement of bonds: While some Lyases might have secondary effects on molecular structure, their primary function is bond cleavage.

4.Formation of bonds: Lyases are primarily involved in breaking bonds, not forming them directly. Bond formation might be a consequence of the elimination reaction, but it's not the main focus.

In summary, Lyases excel at breaking specific chemical bonds within a substrate molecule, playing a crucial role in various cellular processes.