<?xml version='1.0' encoding='UTF-8'?>
<model name="BG51" xmlns="http://www.cellml.org/cellml/1.1#" xmlns:cellml="http://www.cellml.org/cellml/1.1#">
    <!-- Intracellular pH regulation-->
    <units name="dim">
        <unit units="dimensionless"/>
    </units>
    <units name="per_s">
        <unit exponent="-1" units="second"/>
    </units>
    <units name="mol_per_s">
        <unit units="mole"/>
        <unit exponent="-1" units="second"/>
    </units>
    <units name="per_mol">
        <unit exponent="-1" units="mole"/>
    </units>
    <units name="per_mol2">
        <unit exponent="-2" units="mole"/>
    </units>
    <units name="C_per_mol">
        <unit units="coulomb"/>
        <unit exponent="-1" units="mole"/>
    </units>
    <units name="J_per_mol">
        <unit units="joule"/>
        <unit exponent="-1" units="mole"/>
    </units>
    <units name="J_per_C">
        <unit units="joule"/>
        <unit exponent="-1" units="coulomb"/>
    </units>
    <component name="main">
        <variable initial_value="9.64853321e4" name="F" units="C_per_mol"/>
        <variable initial_value="2462.1911" name="RT" units="J_per_mol"/>
        <variable initial_value="-0.057" name="u_e_m" units="J_per_C"/>
        <variable name="epsilon" units="dim"/>
        <math xmlns="http://www.w3.org/1998/Math/MathML">
            <apply>
                <eq/>
                <ci>epsilon</ci>
                <apply>
                    <exp/>
                    <apply>
                        <divide/>
                        <apply>
                            <times/>
                            <ci>F</ci>
                            <ci>u_e_m</ci>
                        </apply>
                        <ci>RT</ci>
                    </apply>
                </apply>
            </apply>
        </math>
        <!-- state variables-->
        <variable initial_value="0" name="q_HCO3_i" units="mole"/>
        <variable initial_value="60" name="q_HCO3_o" units="mole"/>
        <variable initial_value="1e-5" name="K_HCO3_o" units="per_mol"/>
        <variable initial_value="1e-5" name="K_HCO3_i" units="per_mol"/>
        <variable name="Q_HCO3_o" units="dim"/>
        <variable name="Q_HCO3_i" units="dim"/>
        <math xmlns="http://www.w3.org/1998/Math/MathML">
            <apply>
                <eq/>
                <ci>Q_HCO3_o</ci>
                <apply>
                    <times/>
                    <ci>K_HCO3_o</ci>
                    <ci>q_HCO3_o</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>Q_HCO3_i</ci>
                <apply>
                    <times/>
                    <ci>K_HCO3_i</ci>
                    <ci>q_HCO3_i</ci>
                </apply>
            </apply>
        </math>
        <variable name="t" units="second"/>
        <math xmlns="http://www.w3.org/1998/Math/MathML">
            <apply>
                <eq/>
                <apply>
                    <diff/>
                    <bvar>
                        <ci>t</ci>
                    </bvar>
                    <ci>q_HCO3_i</ci>
                </apply>
                <cn cellml:units="mol_per_s">0.5</cn>
            </apply>
        </math>
        <!-- substrate solubilities-->
        <variable name="v_HCO3_m" units="mol_per_s"/>
        <variable initial_value="10.01" name="kappa_HCO3_m" units="mol_per_s"/>
        <math xmlns="http://www.w3.org/1998/Math/MathML">
            <apply>
                <eq/>
                <ci>v_HCO3_m</ci>
                <apply>
                    <times/>
                    <ci>kappa_HCO3_m</ci>
                    <apply>
                        <minus/>
                        <apply>
                            <times/>
                            <ci>Q_HCO3_o</ci>
                            <ci>epsilon</ci>
                        </apply>
                        <ci>Q_HCO3_i</ci>
                    </apply>
                </apply>
            </apply>
        </math>
    </component>
</model>
