This is the last reaction of the electron transport chain in mitochondria and was studied in one of our experiments:
4 Fe²⁺-cyt c+8 H⁺ + O₂ + 4 Fe³⁺-cyt c + 2 H₂O+4 H⁺
a. What is the name of the substrate that changes in color and what is the reason for the change in color?