Figure 2.

(a,c) Experimental determination of the extent of stacking of pea thylakoids as a function of ionic composition of the suspension medium, and (b,d) the corresponding electrostatic repulsion calculated for each particular ionic medium. Either the monovalent or divalent cation concentration was varied while the other was kept constant. Re-drawn from figs. 2, 3 and 5 of Rubin et al. [31] in which the assumed membrane separation was 1 nm in (b) and 4 nm in (d).