An important advance in transport research was the development of methods for making closed membrane vesicles that retain the activity of certain transport systems. One such system uses resealed vesicles from red blood cell membranes, in which the orientation of membrane proteins may be either the same as in the intact cell (right side out) or inverted (inside out). Such vesicles have demonstrable ATP-driven Na^+/K^+ pump activity. By resealing the vesicles in one medium and then placing them in another, it is possible to have ATP, sodium ions, and potassium ions present inside the vesicle, present outside the vesicle, or not present at all. For the inverted vesicles, indicate whether each of the following should be present inside the vesicle, outside the vesicle, or not present at all in order to demonstrate ATP hydrolysis: Na^+, K^+, and ATP. Select all that apply.
Na^+ should be present inside the vesicle.
Na^+ should be present outside the vesicle.
Na^+ should not be present.
K^+ should be present inside the vesicle.
K^+ should be present outside the vesicle.
K^+ should not be present.
ATP should be present inside the vesicle.
ATP should be present outside the vesicle.
ATP should not be present.