facilitated diffusion: protein channels that help sugar molecules move across the membrane from high to low concentration.
Its a beautiful day in the cell. There were many water molecules leaving the cell, because the concentration was to high, to go to work, but there was a rumor going around that there were a couple of sugar molecules roaming the surfaces. Everyone was on the look out.
A couple of days later the rumor became true, some sugar molecules were wandering around. Everyone knew that once the sugar molecule moved across the protein channel, their chances of going back to work are slim.