title: Quantitative analysis of proton movements associated with the uptake of weak carboxylic acids. The yeast Candida utilis as a model.
abstract: A quantitative analysis of the proton movements associated with the initial uptake rate of weak short-chain carboxylic acids was developed in order to estimate proton/carboxylate symports stoichiometries. The yeast Candida utilis was used as a biological model and the deduced equations were applied on the elucidation of the proton/carboxylate symports stoichiometries of lactate, succinate and citrate in a strain of that yeast species at different pH values. At pH 5.0, the proton/lactate and the proton/succinate symport stoichiometry was 1:1. In the cases of the proton/lactate and proton/citrate symports it appears that the stoichiometry ratio increased with increasing extracellular pH.
authors.affiliation: Laboratory of Biology, University of Minho, Braga, Portugal.
authors.forename: F
authors.initials: F
authors.lastname: Cássio
authors.forename: M
authors.initials: M
authors.lastname: Côrte-Real
authors.forename: C
authors.initials: C
authors.lastname: Leão
mesh_terms: D001692:Biological Transport; D002175:Candida; D002264:Carboxylic Acids / Q000737:chemistry / Q000378:metabolism*; D003998:Dicarboxylic Acids / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008433:Mathematics; D008962:Models, Theoretical; D011522:Protons; D014233:Tricarboxylic Acids / Q000378:metabolism
chemical_list: D002264:Carboxylic Acids; D003998:Dicarboxylic Acids; D011522:Protons; D014233:Tricarboxylic Acids