Concept #1: Thermodynamics of Membrane Diffusion: Uncharged Molecule

Example #1: ΔGtransport for Membrane Diffusion of Uncharged Solutes.

Practice: Calculate ΔGtransport for the diffusion of glucose from outside to inside a cell if extracellular [Glucose] = 5 mM, intacellular [Glucose] = 0.5 mM, & the temperature = 20˚C. Would this be an exergonic or endergonic process?

Practice: Calculate ΔGtransport for the diffusion of glucose from inside to outside a cell if extracellular [Glucose] = 1 M, intacellular [Glucose] = 2.0 mM, & the temperature = 20˚C. Would this be a spontaneous or nonspontaneous process?

Practice: Calculate the energy cost (ΔGtransport) of pumping an uncharged solute across a cell’s plasma membrane, against a 1.0 x 104-fold concentration gradient at 25˚C. Would this be an exergonic or endergonic process?