| Comments |
P.6288 right column bottom paragraph: "The osmolarity generated by 60mol/m^3 TMA (trimethylammonium, activity coefficient 1.245 at the concentration of ions in the vacuole: table 5 of Boyd and Gradmann, 2002) is 75 osmol/m^3, while the 60mol/m^3 (activity coefficient 0.88 at the concentration of ions in the vacuole: table 5 of Boyd and Gradmann, 2002) generates 53 osmol/m^3 that is, a total of 75+53=128 osmol/m^3. The seawater osmolarity of standard seawater (salinity=34.32‰, density=1024.3kg/m^3 Table 2, line 8) is 1013 osmol/m^3 (p. 611 of Boyd and Gradmann, 2002 Table 2, row 4) that is, the cell turgor expressed in terms of internal minus external osmolarity is 182 osmol/m^3. Since the mechanism of buoyancy generation by active water transport is most readily considered (and is most energetically efficient) in the occurrence of turgor, it is assumed that turgor is zero (see comments in the main text on the absence of turgor at some life cycle stages in some marine diatoms)." |