Primary Vs Secondary Active Transport -

Every living cell is a bustling city, constantly importing raw materials and exporting waste. To manage this traffic, cells use a sophisticated system of gates and pumps in their outer membrane (the plasma membrane).

Most people know that molecules move from high to low concentration (diffusion). But what happens when a cell needs to move a molecule against its concentration gradient—from low to high? That requires energy. This process is called . primary vs secondary active transport