<span>Active
transport requires ATP to enable a carrier protein to move from low
concentration region to a higher concentration region.
While </span><span>diffusion
occurs because of the movement of molecules from the region of higher
concentration to the region of lower concentration. This movement of
molecules occurs due to a thermal motion. Diffusion normally occurs
between two compartments having difference in concentration. In case of
fluid it moves from the region of higher concentration to the region of
concentration until a balance is reached. The process of diffusion is
very important for the humans as well. The oxygen that humans breathe in
gets diffused with the blood.<span> </span></span>
