You are employed at a biotech company, working on a new drug, named XYZ. Your boss wants to know how this compound move into red blood cells, and what its concentration will be in red blood cells. He has provided you with plenty of samples of drug XYZ, and you have the means to measure its concentration (mol^-1) inside and outside red blood cells, as well as the concentration of any metabolites of drug XYZ. He has now asked you for a protocol. Provide protocol to test this options: a. The drug will move into red blood cells by diffusion, but may be metabolized to another compound over time.
b. The drug will move into red blood cells by diffusion and, with time, have equal concentrations in red blood cells and plasma.
c. The drug will enter red blood cells by protein-facilitated diffusion, and, with time, have equal concentrations in red blood cells and plasma.
d. The drug may be actively taken up by the red blood cells by protein-mediated transport.