Figure. 18.

Depending on the system of interest, the involved levels of complexity are intertwined differently. (a) The properties of individual biopolymer filaments can be explained by its respective monomer level and reconstituted biopolymer solutions forming entangled networks are understood from a single filament level (b). As soon as elements start to bridge more levels of complexity, the situation quickly becomes more complicated. (c) Cross-linked actin networks, for instance, are more difficult to model than entangled solutions. Closed feedback loops across multiple levels (d), such as transiently cross-linked actin networks, inhibit further coarse-graining and hence make it a demanding task for theoretical modeling.