This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Misc., Subject name: Physiology
[{'content': 'Gibbs-Donnan effect is seen on the distribution of: \nSelect and explain. \nA. Diffusible ions, B. Diffusible + Non-diffusible ions, C. Non-diffusible ions, D. Only proteins', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (A) Diffusible ions # When there is an ion on one side of a membrane that cannot diffuse through the membrane, the distribution of other ions to which the membrane is permeable is affected in a predictable way. For example, the negative charge of a nondiffusible anion hinders diffusion of the diffusible cations and favors diffusion of the diffusible anions. Consider the following situation, in which the membrane (m) between compartments X and Y is impermeable to Prot out freely permeable to K+ and Cl\\ Assume that the concentrations of the anions and of the cations on the two sides are initially equal. Cl\' diffuses down its concentration gradient from Y to X, and K+ moves with the negatively charged Cl", maintaining electroneutrality on side Y. Therefore, at equilibrium', 'role': 'assistant'}]