What is the process of diffusion?

Diffusion refers to the movement of molecules from an area of high concentration to an area of low concentration. This process occurs naturally due to the kinetic energy of molecules, which causes them to move randomly. When molecules are in high concentration, they are more likely to collide with one another, prompting them to spread out and fill the available space more uniformly. This movement continues until equilibrium is reached, where the concentration is equal across the space.

This process is vital for many biological systems, including gas exchange in the lungs and the distribution of nutrients and waste products in cells. It is a passive transport mechanism, meaning it does not require energy input from the cell, contrasting with active transport processes that do require energy to move substances against their concentration gradient.