1. a.3.1 Cytochrome c covalently-bound heme completes the core ! Cytochrome c core: 3 helices; folded leaf, opened 1c2r d1c2ra_ A:16-22,24-30,33-38,41-45,103-116 1vyd d1vyda_ A:16-22,24-30,33-38,41-45,103-116