Let me share with you a comparison between prosthetic group and coenzyme.
| Aspect | Prosthetic Group | Coenzyme |
| Introduction | A non-protein that is tightly bound and is permanent component of an enzyme’s structure. | A small non-protein part that assists an enzyme in its catalytic function. |
| Nature | Can be organic or inorganic | Typically organic molecules |
| Attachment to enzyme | Tightly bound to the enzyme, often through covalent bonds | Loosely bound to the enzyme |
| Function | Essential for the catalytic activity of the enzyme | Facilitates enzymatic reactions |
| Examples | · Heme group in catalase · Biotin in carboxylases | · NAD+ · FAD · coenzyme A · Vitamin-derived coenzymes like thiamine pyrophosphate (TPP) |
| Regeneration | Usually does not need to be regenerated as it remains bound to the enzyme | Often needs to be regenerated after each catalytic cycle |
| Role in enzymatic reactions | Directly participates in the catalysis of reactions | Acts as a carrier of specific functional groups or electrons during reactions |
| Binding site on enzyme | Typically binds at the active site of the enzyme | May bind at the active site or at allosteric sites on the enzyme |
| Stability | Generally stable, often not released during the catalytic cycle | May dissociate from the enzyme after the reaction, allowing it to participate in multiple cycles |
| Concentration in cells | Often present in low concentrations due to their permanence | Present in higher concentrations as they are recycled in multiple enzymatic reactions |