Iron
Iron is the most common transition metal in biological systems.
Due to its special importance, many organisms have bioligands and proteins, which are solely responsible for the absorption, transport and storage of iron.
Iron is found in the center of porphyrin ligands (so-called haem iron), in the form of iron-sulfur clusters and bound to donor sites of proteins.
Biological iron compounds have the following functions, among others:
- Oxygen transport (Haemoglobin)
- Electron transfer catalysis (Rubredoxin, Ferredoxin)
- Hydroxylation (Hydroxylases)
- Utilization of H2O2 (Peroxidases)
- Hydrolysis of oligomeric and polymeric phophate groups (Phosphatases)
- Dismutation of O2 (Superoxide Dismutases)