Biochemistry Questions / Compare the process of dehydrating K+ ions versus Na+ ions in ion channels, and explain why it requires more energy to remove water molecules from Na+.

Ion channels must dehydrate K+ and Na+ ions, in order to allow the selective transport of only ions. More energy is required to dehydrate Na+ due to the smaller size of the ions, allowing the water molecules to be pulled in to the ion more tightly. This prevents the degradation of proton gradients, and other potential energy sources.

There are more water molecules bound to K+ ions (8), reducing the energy each one interacts with the central ion. This makes it easier to remove than the 6 water molecules hydrating an Na+ ion.