Consider the transport of K⁺ from the blood (where its concentration is about 4 mM) into an erythrocyte that contains 150 mM K⁺. The transmembrane potential is about 60 mV, inside negative relative to outside. What is the free-energy change for this transport process? (These values may be of use to you: R = 8.315 J/mol ^.K; T = 298 K; (Faraday constant) = 96,480 J/V; N = 6.022 × 10²³/mol.)

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Quizplus · Accepted Answer

The free-energy change (ΔG) for the transport of ions across a membrane can be calculated using the Nernst equation: ΔG = RT ln([K⁺]_inside/[K⁺]_outside) + zFΔψ. Substituting the given values: ΔG = (8.315 J/mol·K)(298 K) ln(150/4) + (1)(96,480 J/V·mol)(-0.060 V). This calculation results in approximately 15 kJ/mol.

Consider the Transport of K+ from the Blood (Where Its

Consider the Transport of K⁺ from the Blood (Where Its