Diffusion vs. Active Transport

The user wants to know about the difference between diffusion and active transport.

Diffusion and active transport are two fundamental processes that cells use to move molecules across their membranes.

Diffusion is a passive process where molecules move from an area of higher concentration to an area of lower concentration, driven by the natural tendency of particles to spread out and reach equilibrium. This process does not require energy input from the cell. It is important for small, non-polar molecules like oxygen and carbon dioxide, as well as for small polar molecules like water.

Active transport, on the other hand, is a process that requires energy to move molecules against their concentration gradient, from an area of lower concentration to an area of higher concentration. This process is essential for the transport of ions (like sodium, potassium, and calcium) and larger molecules (like glucose and amino acids) across the cell membrane. Active transport is carried out by specific proteins called pumps, such as the sodium-potassium pump, which use energy from ATP to pump ions across the membrane.

In summary, the main difference between diffusion and active transport is that diffusion is a passive process driven by the concentration gradient, while active transport is an energy-requiring process that can move molecules against their concentration gradient.