Contrasting views on the organization of cytoplasm

Abstract

The widely held conception of cytoplasm as a concentrated solution of dissolved proteins and other macromolecules, metabolites and inorganic ions, within which the various organelles and other formed elements are suspended appears to be a gross over-simplification. Evidence to be reviewed briefly here, from a wide variety of experiments and cell types, indicates that a much more extensive organization exists, in animal cell cytoplasm at least. Results from experiments on dextran sulfate permeabilized L-929 cells will be presented which support that organized paradigm. It seems likely that this intracellular architecture also exerts a strong influence on the water in the regions adjacent to it, resulting in the generation of altered aqueous phase physical properties compared to those of ordinary aqueous solutions. This analysis suggests consequences of far reaching importance to our understanding of cell structure and function.