73.  How does the potassium channel maintain selectivity for potassium versus sodium ions?  (MARK ALL THAT APPLY) Group of answer choices a. The partial negative charge of carbonyls in the pore is precisely balanced with the positive charge of only potassium ions. b. Potassium can form more interactions with the pore, resulting in desolvation of attached water. c. Sodium is too big to fit through the pore. d. Sodium can form more interactions with the pore, resulting in desolvation of attached water. e. On the basis of ionic radius.

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e. The average human skin cell f. The length of the tip of your thumb (measured from first knuckle to the edge of your nail) 2. Consider two molecules, X and Y. a. X is able to dissolve in water. What does this imply about the favorability of interactions between molecules of X versus interactions between X and water? b. Y is unable to dissolve in water. What does this imply about the favorability of interactions between molecules of Y versus interactions between Y and water? Draw what happens to Y in water. 1

powders and granules dosage forms have faster dissolution rate than capsules and tablets  ,why?