Figure 1. Flux control in radical chain reactions in relation to biological aging. Radical chain reactions have three kinetically independent steps: initiation, propagation and termination. The prevention of initiation is the designated task of antioxidant enzymes like SOD. Accelerating termination is the designated task of chain-breaking antioxidants like vitamin E. Propagation, though, has never been shown to be specifically influenced by any biomolecule [