A trifunctional enzyme with glutathione S transferase, glutathione peroxidase and superoxide dismutase activity ScienceDirect GLUTATHIONE PEROXIDASE, SELENIUM AND VITAMIN E Free radicals "steal" electrons from the chemical structures that make up cell membranes. When the structures making up the cell membranes loose electrons they too become Figure 1 from Glutathione S transferase, catalase, superoxide dismutase, glutathione peroxidase, and lipid peroxidation as a biomarkers of oxidative stress in snails: A review Semantic Scholar Glutathione Peroxidase (GPX) Activity Assay Kit (Colorimetric) RayBiotech Oxidative stress in Portuguese children with Down syndrome Human Glutathione Peroxidase 1 ELISA Kit (ab315322) Abcam