Question

A cell is found with the following concentrations of solutes inside

2. A cell is found with the following concentrations of solutes inside: 300 mM glucose and 150 mM Cach. The cell membrane of these cells is made with pores which are permeable to glucose but not to ions. These cells are isolated and then placed in a 150 mM CaCl2. What happened to the cells after the solution and the cells come to equilibrium? (4 Points) a. They cells remain the same size b. The cells have increased in size; they swell c. The cells have decreased in size; they shrink d. There is not enough information given in the problem to determine what happens

Answer 1

The correct answer is option C, the cells have decreased size; they shrink.

As the cell membrane is permeable only for glucose, when it is placed in a solution of 150mM CaCl_2, the cell becomes hypertonic with respect to glucose as the solution outside the cell has lower concentration of glucose with respect to the concentration of glucose inside the cell. Therefore, glucose will pass through the pores of the cell and move towards the solution outside till a equilibrium is reached (concentration of glucose on either sides of the cell membrane becomes equal).

For additional information, when a cell is placed in a solution there can be 3 possible outcomes:

• Hypertonic solution: Where the concentration of permeable contents have a higher concentration inside the cell.
• Hypotonic solution: Where the concentration of permeable contents have a higher concentration outside the cell.
• Isotonic solution: Where the concentration of permeable contents have equal concentration on either side of the cell membrane.