Question

Because a cell’s volume increases along with the cube of its radius, whereas its surface area increases only with the radius’s square, a cell’s size must be tightly controlled; lest rate of solute transport through the cell’s surface membrane be inadequate to nourish the entire volume comprising the cell’s interior. One way to control cell size is to regulate the pumping of solutes, such as the pumping of sodium out of (or, for other solutes, into) the cell. Synthesizing information from throughout the course, provide a brief description of how pumping sodium out of the cell may be used to affect cell size

Answer 1

Answer :

Sodium potassium pump work against concentration gradient. It pumps 3 sodium out and 2 potassium in. This causes osmotic imbalance and water flux. The interior of cell becomes more hypotonic.

Once sodium potassium pump is inhibited by ouabain passive leakage occurs and cell swells. Sodium potassium pump maintain cell volume. If it overwork cell size decrease and if it stops working cell swells up.

Increase in volume means increase in surface area but to a lower extent than volume.