The energy driving the movement of molecules during passive transport comes from differences in the concentration of the molecules on either side of the membrane with the molecules tending to move from the side of higher concentration to the side of lower concentration because of their net thermal movement.
Because there are two major ways that molecules can be moved across a membrane, and the distinction has to do with whether or not cell energy is used. Passive mechanisms like diffusion use no energy, while active transport requires energy to get done
How is energy used to move?
Molecules do not stop moving once they reach equilibrium. Passive Transport (no energy needed). The movement of particles from an area of high concentration to low concentration. Particles pass right through the cell membrane. the (passive) movement of large particles or substances across the cell membrane through protein channels.
