Answer
🧬 Peroxidase and Catalase Enzymes: Role of Haem
🔍 What Are Peroxidase and Catalase?
Peroxidase and catalase are enzymes found in many living organisms. Their primary function is to protect cells from oxidative damage by breaking down hydrogen peroxide (H2O2), a reactive oxygen species that can be toxic at high concentrations.
⚙️ Catalytic Function
Both enzymes catalyze the reaction:
2H2O2 → 2H2O + O2
This reaction helps eliminate hydrogen peroxide from the cell, preventing oxidative stress.
🔗 Role of Haem (Heme) as a Prosthetic Group
- A prosthetic group is a non-protein component tightly bound to an enzyme, essential for its function.
- In peroxidase and catalase, the prosthetic group is haem.
- The haem group contains an iron (Fe) atom and is crucial for redox reactions involved in hydrogen peroxide breakdown.
🧠 Biological Importance
- Detoxification: Removes harmful hydrogen peroxide from cells.
- Metabolism: Active in high-metabolism tissues like liver and kidney.
- Defense: Part of the organism’s antioxidant defense system.
📌 Summary Table
| Enzyme | Function | Prosthetic Group |
|---|---|---|
| Peroxidase | Uses electron donors to reduce H2O2 | Haem |
| Catalase | Directly decomposes H2O2 to H2O and O2 | Haem |