Which of the following statements is FALSE? The critical concentration of actin for each actin filament is the concentration of free G-actin at which addition and loss are balanced. The actin filament has a gradient of actin bound to ATP, actin bound to ADP-Pi and actin bound to ADP. The rate of actin subunit dissociation from a filament is dependent on the concentration of free G-actin. Actin treadmilling is caused by the difference in G-actin critical concentrations between the two ends.