Fig. 3.

Total protein gradients could act across a range of cell sizes. (a) At a very high phosphatase rate (k_p=100 s⁻¹), the gradient is predicted to be appreciable in cells as small as a bacterium. (b) Animal cells and (c) oocytes/embryos can experience total protein gradients, simply by reducing the phosphatase rate constant, k_p, according to the cell dimension. Diffusion coefficients D_A=1 μm²s⁻¹, D_B=10 μm²s⁻¹, kinase rate constant k_k=100 μm/s, overall protein concentration 1 μM in all panels.