A concentration gradient in the electrolyte is illustrated. ·If the electrolyte is unstirred, the gradiant causes H-ion diffusion to the surface, where they capture electrons (reduction) to become ...

Diffusion Substances move from a high to a lower concentration down a concentration gradient Carbon dioxide, oxygen, water, food substances, wastes, eg urea No Osmosis Water moves from a high to a ...

It occurs down a concentration gradient - molecules move from an area of high to lower concentration. This does not require a supply of energy because diffusion is a spontaneous process.

The presence of a Dpp gradient ... its strongest concentration (visualized as the brightest green fluorescence) down the center of the imaginal disc. The posterior and anterior diffusion of ...