Which is correct if it is not correct, correct it.

Simple or facilitated diffusion requires cellular energy.​

Diffusion results in a net flow of solute down a concentration gradient, while active transport works against the concentration gradient.​

Secondary active transport uses energy to set up a concentration gradient which then allows some passive diffusion to occur, recapturing some of the energy expended.​

Membrane proteins are required for all membrane transport into and out of cells.​