What is the maximum ratio of [I^â]_in to [I^â]_out that could be maintained at equilibrium if the Na⁺ gradient is kept constant (by other transport processes) such that transport of Na⁺ into the cell has a ?G of â30 kJ/mol. Assume the membrane potential is â155 mV (inside negative) and that transport of iodide does not affect the size of the Na⁺ gradient. Perform your calculation at body temperature (37Â°C).

Hint: You will need to balance unfavorable the iodide ion transport against this favorable energy for Na+ transport.

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Deanna HettingerLv2

28 Sep 2019

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