Consider the transport of glucose into an erythrocyte by facilitated diffusion. What is the free-energy change for glucose uptake into the cell when the glucose concentrations are 5 mM on the outside and 0.1 mM on the inside? (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 for the transport of a molecule across a membrane by facilitated diffusion can be calculated using the equation ΔG = RT ln(C2/C1), where R is the gas constant, T is the temperature in Kelvin, and C2 and C1 are the final and initial concentrations, respectively. Plugging in the given values (R = 8.315 J/mol·K, T = 298 K, C2 = 0.1 mM, and C1 = 5 mM), we get a positive value indicating energy is required for the transport against the concentration gradient, which is consistent with the process of facilitated diffusion. The calculation yields a value around 10 kJ/mol, indicating that option B is correct.

Consider the Transport of Glucose into an Erythrocyte by Facilitated