Fig. 18.11  (a) Polymerization of actin.  (b) Different rates of polymerization occur with and without nucleating particles.


Fig. 18.13a  Demonstration that polymerization occurs faster at the + end of the F-actin filament.

Fig. 18.13b  Capping proteins attached to the end of F-actin prevents further polymerization or depolymerization at that end.

Fig. 18.13c  Actin monomers can be treadmilled from one end of the growing actin to the other at a monomer concentration between the  critical concentration of the - and + ends.

Fig. 18.12  The critical concentration Cc- is illustrated as the actin concentration at which filaments begin to form.

Fig. 18.15  Action of Profilin on acceleration of ATP-G-actin polymerization.



Fig. 18.20  Different types of myosin motors.

Fig. 18.21a  Membrane bound myosins.

Fig. 18.21b  The structure of myosin II in bundles used in muscles.

Fig. 18.37a  The localization and contraction of myosin II and actin filaments during cytokinesis.

Fig. 18.25  Energy dependent movement of myosin motor along actin filament.


Fig. 18.40  Myosin motors bound to organelles move along actin tracks to create cytoplasmic streaming in Nitella cells.


Fig. 18.42  Action of myosin and actin in cell movement.


Fig. 18.43  Localization of myosin I at the leading edge of moving cell.  The localization of myosin II at the lagging edge ofa moving cell.