All movement, including that of diffusing molecules, requires a small expenditure of energy; what is the source of the energy that makes diffusion across the cell membrane possible?

Question

Quizplus · Accepted Answer

Thermal energy present in the extracellular environment provides the energy for diffusion across the cell membrane. This thermal energy causes the molecules to move randomly, and some of them may collide with the membrane and pass through it. No ATP hydrolysis or chemical reaction with the membrane is involved, and gravity does not play a significant role in the movement of molecules across the cell membrane.

All Movement, Including That of Diffusing Molecules, Requires a Small