Textbook Problem

Using the principle of diffusion, a dialysis machine removes waste solutes from a patient’s blood. Imagine blood runs through a cylinder wherein diffusion can occur across an artificial selectively permeable membrane to a saline solution on the other side. Which of the following statements is correct?

a. Solutes move from lower to higher concentraction.

b. The concentration gradient is lower in the patient’s blood than in the saline solution wash.

c. The solutes are transported through a symport in the blood cell membrane.

d. The saline solution has a lower concentration gradient of solute than the blood.

e. The waste solutes are actively transported from the blood.