Explain why facilitated diffusion does not require energy from a cell.

The solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. This process is called passive transport or facilitated diffusion, and does not require energy.

The solute can move "downhill," from districts of higher to lower fixation, depending on the specificity of the protein bearer to go through the film. This procedure is called uninvolved transport or encouraged dissemination, and does not require vitality.