it is assumed that the effect of the phosphate and acetate buffer solutions on the cell , decreasing the rate of penetration , is due ( 1 ) to the penetration of these acids into the protoplasm as undissociated molecules , which dissociate upon entrance and lower the ph value of the protoplasm or to their action on the surface of the protoplasm , ( 2 ) to the effect of base cations on the protoplasm ( either at the surface or in the interior ) , and ( 3 ) possibly to the effect of certain anions .
C0031603
phosphate
C0003075
anions