Active TransportActive Transport

• The movement of particles across the plasma membrane against the concentration gradient, that is from a region of low concentration to a region of high concentration.

• Active transport also requires specific carrier proteins that bind to the substance to be transported, enabling the substance to pass rapidly across the plasma membrane.

• Sometimes the carrier proteins are referred to biological pumps.

• Active transport requires an input of energy provided by ATP. So, it can only take place in living organism.

Sodium-potassium pumpSodium-potassium pump

Ion intake by root hairs of a plant

Mineral ions are absorbed across the membranes of the root hairs by active transport.