Effects of relative viscosity in the presence of added sucrose on kcat and kcat/Km for GalNAcK, HSK, and hexokinase at 25 °C. When small effects were observed (kcat/Km for GalNAcK, kcat for GalNAcK, and kcat for hexokinase) the points were fit to a line using linear least squares regression. Slopes of those lines are, respectively, 0.22, 0.15, and 0.11. Similar results were obtained using trehalose and polyethylene glycol 300 as viscosogens.