What Are The Concepts Of Active And Passive Transport?

Active transport is the movement of the particles against a concentration gradient like through a biological membrane separating low density and high density. For example, Chloroform, ethanol and water do not require active transport to move across a membrane. Some ions like Na, K, Ca and Mg also requires ionic pumps and ion channels for active transportation.

In passive transport molecules move in their natural way and chemical energy is not required. Passive transport include osmosis, filtration, diffusion and facilitated diffusion. In this case molecules move down the concentration gradient. Like movement of molecules within or out the inter-cellular spaces.