Which prosthetic groups gets attached to the enzyme at the time of reaction?

Coenzymes

The correct answer is option 3. Coenzymes.

Out of the choices you provided, Coenzymes are the prosthetic groups that get attached to the enzyme at the time of reaction.

Here's a breakdown of the terms:

Inhibitors: These molecules bind to enzymes and hinder their activity, slowing down or stopping the reaction.

Cofactors: This is a broader term encompassing both coenzymes and metal ions. Cofactors are essential for enzyme activity, but not all are attached directly during the reaction.

Coenzymes: These are organic molecules that act as prosthetic groups, tightly binding to specific enzymes and participating directly in the catalytic cycle. They often undergo temporary changes during the reaction and become regenerated afterwards.

Messengers: These are signaling molecules that travel within cells or between cells to coordinate various processes. They are not directly involved in enzyme activity.

Therefore, coenzymes are the specific type of cofactor that directly attaches to the enzyme during the reaction and plays a crucial role in the catalytic process.