Final answer:
The lipid solubility of the ion is not a determinant of the equilibrium potential for an ion; the relevant factors include concentration gradient, charge, and valence of the ion.
Step-by-step explanation:
The determinant of the magnitude and direction of the equilibrium potential for an ion that is NOT relevant is lipid solubility of the ion (Option B). The Nernst equation, which predicts the equilibrium potential, considers the concentration gradient, charge of the ion, and valence of the ion. The lipid solubility does not affect the equilibrium potential directly because ions move across cell membranes through specific protein channels rather than dissolving in the lipid bilayer.
The lipid solubility of the ion is NOT a determinant of the magnitude and direction of the equilibrium potential for an ion.
The equilibrium potential for an ion is determined by the concentration gradient, charge of the ion, and valence of the ion.
The concentration gradient refers to the difference in concentration of the ion inside and outside the cell. The charge of the ion refers to whether it is positively or negatively charged. The valence of the ion refers to the number of ions the ion can form.