Explain active transport and give an example to demonstrate this in both plants and animals

Active transport is the movement of a substance from an area of low concentration to an area of high concentration. This process requires energy, usually in the form of ATP, as the direction of movement is against the net movement of the substance (against its concentration gradient). For example, in plants active transport is required for the uptake of mineral ions into root hair cells. This is because there is a higher concentration of the mineral ions in the root hair cell than in the soil and therefore requires ATP. In animals, active transport is required for the absorption of glucose. In this process, sodium ions move into the blood stream out of the ileum by active transport via the sodium-potassium pump creating a concentration gradient. This then causes sodium ions to diffuse out of the lumen of the ileum into the cells lining the ileum along with glucose. Glucose is then able to diffuse down the concentration into the bloodstream by facilitated diffusion.