A few questions to wrap up this topic:
- When a red blood cell is placed in a hypertonic solution, I can understand why the water molecules from the cell diffuse out to the solution to reach equilibrium, but why doesn't the solute molecules in the hypertonic solution go to the cell? I know some solutes cannot diffuse through the membrane easily, but they can go through the protein channels etc.. Or do these two processes happen simultaneously, but because diffusion of water is obviously faster, the net movement occurs faster?
- I know now how water molecules or oxygen can readily diffuse through the membrane, through Aquaporins. But, my school textbook says protein channels/carriers have a hypdrophillic lining in them, so that the polar substances can readily diffuse through them in the process of facilitated diffusion. BUT, the Nature of Bio says that both non polar and polar substances can go through these protein molecules. Can anyone please clarify? Thanks
Am I going into toooooo much detail? Haha,
someone needs to keep this thread alive!