||Missner A, Kügler P, Saparov SM, Sommer K, Mathai JC, Zeidel ML, Pohl P. Carbon dioxide transport through membranes. J Biol Chem. 2008 Sep 12 283(37):25340-7. doi: 10.1074/jbc.M800096200. p.25340 right column top paragraph & 2nd paragraphPubMed ID18617525
||"The number was calculated
assuming that NH3 and CO2 have comparable membrane
diffusivities and that neither one of them belongs to those
extremely rare exceptions from Overtone’s rule (6, 7) so that the
proportionality between PM [permeability] and the biphasic partition coefficient
(water/organic solvent) applies as shown in Equation 1, PM,CO2=(PM,NH3)?KCO2/KNH3=12cm/sec (Eq. 1) where KCO2~1.5 (8), KNH3~0.002 (6), and PM,NH3=0.016cm/s (9)."
||"A PM,CO2 of 12 cm/s suggests that the lipid matrix of biological
membranes cannot act as a barrier to CO2 diffusion. In fact, a
stagnant water layer adjacent to the membrane that has the same
thickness (d) as the membrane would generate the same resistance
to CO2 flow as is caused by the membrane itself."