On the fractal nature of cytoplasm.

On the basis of a quantification of the fractal dimension, D, in micrographs of cytoskeleton components or microtrabecular lattice, we propose that the cellular cytoplasm can be described as a percolation cluster, a sort of 'random fractal'. Our hypothesis deals with: (i) the existence of the percolation threshold--a remarkable property of percolation processes; and (ii) the reactivity increase--when enzymes, or targets, and substrates, or effectors, coexist in the same topological dimension.