Linked Life Data

8369403

Source:http://linkedlifedata.com/resource/pubmed/id/8369403

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1993-10-13
pubmed:abstractText
This paper presents a simple model to describe experimental data on weak acid transport across planar bilayer lipid membrane separating two buffered solutions. The model takes into account multiple proton-transfer reactions occurring in the unstirred layers (ULs) adjacent to the membrane. Differential equations of the model are shown to be reduced to a set of nonlinear algebraic equations. Since the latter equations depend monotonically on unknown variables, they can be easily solved numerically, using bisection method. For the particular system studied experimentally (with acetate as the weak acid and TRIS+MES as the buffer mixture) pH profiles in the ULs are calculated from the model. These results are compared with experimental data obtained using pH microelectrode. The agreement between theoretical and experimental pH profiles is found to be satisfactory. The most pronounced deviations are observed at the UL/bulk solution boundary. To obtain a better correlation between the theoretical and experimental results, two other, less idealized models are considered. They take into account, respectively, (a) the electric field arising in the ULs from ion diffusion and (b) finiteness of the rates of proton-transfer reactions. However, both acetate membrane fluxes and pH profiles in the ULs computed from these models are found to be close to those of the simple model. One can thus conclude that the difference between experimental and theoretical pH profiles is due to the inconsistency of the generally accepted model of the "unstirred layer", assuming the existence of a strict boundary between the regions of "pure diffusion" and "ideal stirring".
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/8369403-1764459, http://linkedlifedata.com/resource/pubmed/commentcorrection/8369403-1953784, http://linkedlifedata.com/resource/pubmed/commentcorrection/8369403-2764883, http://linkedlifedata.com/resource/pubmed/commentcorrection/8369403-408462, http://linkedlifedata.com/resource/pubmed/commentcorrection/8369403-4752218, http://linkedlifedata.com/resource/pubmed/commentcorrection/8369403-4854915, http://linkedlifedata.com/resource/pubmed/commentcorrection/8369403-5063846, http://linkedlifedata.com/resource/pubmed/commentcorrection/8369403-6359229, http://linkedlifedata.com/resource/pubmed/commentcorrection/8369403-6377340, http://linkedlifedata.com/resource/pubmed/commentcorrection/8369403-6699907, http://linkedlifedata.com/resource/pubmed/commentcorrection/8369403-7097246, http://linkedlifedata.com/resource/pubmed/commentcorrection/8369403-7104333, http://linkedlifedata.com/resource/pubmed/commentcorrection/8369403-831787
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-3495
pubmed:author
pubmed:issnType
Print
pubmed:volume
64
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1701-10
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Weak acid transport across bilayer lipid membrane in the presence of buffers. Theoretical and experimental pH profiles in the unstirred layers.
pubmed:affiliation
A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't