Random Molecular Movement

What is Random Molecular Movement?

Molecules and ions possess kinetic energy and are in constant motion, colliding and changing direction unpredictably. No individual particle has a preferred direction, but where particles are unevenly distributed this random motion produces a predictable net movement from the crowded region to the less crowded one. It is the source of the energy for diffusion and osmosis, so neither process requires energy from the cell.

This definition is part of the Movement Into and Out of Cells chapter in Cambridge O Level Biology.

Concepts related to Random Molecular Movement

• kinetic energy
• net movement
• dynamic equilibrium
• Concentration Gradient