Active Transport

Key Stage 4

Active transport is the movement of a substance from a region of low concentration to a region of high concentration against the concentration gradient.

Active transport requires energy to move a substance against the concentration gradient.

Active transport is an essential process for all living organisms. It is used to take in nutrients when there is not a high enough concentration to diffuse into the organism.

Active transport allows organisms to take in nutrients more quickly and in greater quantities than diffusion.

Active transport takes place across the cell membrane where there are special protein molecules which act as pumps to move substances from one side of the cell membrane to the other. Since the cell membrane is selectively permeable those substances cannot diffuse back again.