Animation - How Diffusion Works

How are molecules distributed in the environment?

As explained in this animation, the random movement of molecules in a gas or a liquid will cause the molecules to become evenly distributed in the environment. If we look at the environments in which cells exist, for example inside a body or in a pond, we do not see an even distribution of molecules associated with life. Cells prevent, control, and even work counter to diffusion to create concentration gradients, to exclude waste or harmful materials, and to store needed materials. Life can be described as a process of controlling the diffusion of molecules.

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