Describe the similarities and differences between simple diffusion, facilitated diffusion, and active transport. Be sure to discuss how each works in comparison to the concentration gradient and energy cost to the cell.

Similarities:

The facilitated diffusion, simple diffusion and active transport are used for the transportation of molecules from one side of the membrane to the other side. These all processes are important for the cell survival and maintains the concentration gradient of the cell.

Differences:

The simple diffusion do not require any carrier molecule or ATP source for the transport of molecules. The facilitated diffusion requires the carrier molecule for its transport and no energy is required for their transport. The diffusion transport molecules along the concentration gradient. Active transport require energy molecule for the transport of substance along the concentration gradient.