How could you demonstrate the process of facilitated diffusion?
Actually, for facilitated diffusion, when the proteins become denatured, this generally causes the membrane to become porous, so there is a sudden increase in the diffusion of all substances. We did an experiment demonstrating this last year, IIRC using beetroot cores. The cores were placed in test tubes which had been heated to different temperatures (ranging from RT to 70deg), and were then incubated for some time. The cores were then removed, and the liquid from the tubes analysed in a visible light spectrometer, to determine the level of transmittance. There was a gradual increase in transmittance up to a point due to the pigment leaving the cells by facilitated diffusion, until the point where the proteins became denatured, when there was a big drop in transmittance as the pigment could freely leave the cells.
