Wabash College 1 article published in JoVE Biochemistry Modeling an Enzyme Active Site using Molecular Visualization Freeware Kristen Procko1, Sandy Bakheet1, Josh T. Beckham1, Margaret A. Franzen2, Henry Jakubowski3, Walter R. P. Novak4 1The University of Texas at Austin, 2Mount Mary University, 3College of St. Benedict/St. John’s University, 4Wabash College A key skill in biomolecular modeling is displaying and annotating active sites in proteins. This technique is demonstrated using four popular free programs for macromolecular visualization: iCn3D, Jmol, PyMOL, and UCSF ChimeraX.