Consider a simple model cell that consists of cytoplasm surrounded by a cell membrane. The cell’s initial volume is 3 nL and contains 0.3 M protein and 0.2M Ca++. The cell is placed into a 500mL tank of 0.1 M calcium chloride. Neither Ca++ nor Cl- can cross the membrane.

(a) Initially is the solution, isotonic, hypertonic, or hypotonic with respect to the cells cytoplasm?
(b) What occurs as the cell achieves equilibrium?
(c) What is the final osmolarity of the cell and solution?
(d) What is the final cell volume?
(e) What average charge do the proteins have to have to maintain cellular equilibrium?