As we know active transport implies the movement of chemical compounds/ions across the membrane using energy (ATP) to do so. One of the most common examples of active transport is the kown sodium-potassium pump, a mechanism that is found in all animal life forms. Another example is plant root cells, these need to absorb mineral salts from the ground, however, these salts tend to be very diluted so active transport allows these salts to be absorbed by the plants against the concentration gradient.