Destroys radicals which are normally produced within the cells and which are toxic to biological systems. 2 Fe(II)-[cytochrome c] + 2 H(+) + H2O2 = 2 Fe(III)-[cytochrome c] + 2 H2O Binds 1 heme b (iron(II)-protoporphyrin IX) group per subunit. Forms a one-to-one complex with cytochrome c. Belongs to the peroxidase family. Cytochrome c peroxidase subfamily.