Here are some common examples of metal complexes found in nature:
1. Hemoglobin
- Metal: Iron (Fe²⁺)
- Ligands: Porphyrin ring (nitrogen atoms) + O₂
- Role: Carries oxygen in red blood cells
2. Myoglobin
- Metal: Iron (Fe²⁺)
- Ligands: Porphyrin ring + O₂
- Role: Stores oxygen in muscles
3. Chlorophyll
- Metal: Magnesium (Mg²⁺)
- Ligands: Porphyrin ring
- Role: Captures sunlight for photosynthesis
4. Vitamin B₁₂
- Metal: Cobalt (Co³⁺)
- Ligands: Corrin ring + CN⁻ or other groups
- Role: Helps in blood formation and nerve function
5. Cytochromes
- Metal: Iron (Fe²⁺/Fe³⁺)
- Ligands: Porphyrin ring
- Role: Transfers electrons in cellular respiration
6. Enzyme Cofactors
- Metals: Zn²⁺, Mg²⁺, Mn²⁺, Cu²⁺
- Ligands: Amino acids or other molecules
- Role: Activate enzymes, help in biochemical reactions
Simple idea:
- Many biological molecules use metal ions as the central part of a complex to carry oxygen, transfer electrons, or capture light.