| R02810 | [Fig] | 2 I- + H2O2 | <=> | I2 + 2 H2O |
| R03973 | [Fig] | HI + 3,5-Diiodo-L-tyrosine | <=> | 3-Iodo-L-tyrosine + I2 |
| R03539 | [Fig] | HI + 3-Iodo-L-tyrosine | <=> | I2 + L-Tyrosine |
| R03953 | [Fig] | 3-Iodo-L-tyrosine + 3,5-Diiodo-L-tyrosine + H2O2 | <=> | 3,3'5-Triiodo-L-thyronine + 2-Aminoacrylate + 2 H2O |
| R03208 | [Fig] | 2 3,5-Diiodo-L-tyrosine + H2O2 | <=> | 3,5,3'5'-Tetraiodo-L-thyronine + 2-Aminoacrylate + 2 H2O |
| Haem |