one peculiarity of the system is that it is the release of actin from myosin—not the binding of the fibers—that requires energy. When an organism dies, and the source of energy is lost, the muscle fibers, unable to unclasp their fists, are caught in a permanent grip—bound. The cellular ropes in every muscle tighten. The body hardens and contracts into the permanent clasp of death—the phenomenon that we call rigor mortis).
