A cell must continually expend energy or it will die. Some of the energy is used for "housekeeping" chores like pumping ions and replacing used molecules. But there's more to life than maintenance and cells need extra bursts of energy for specialized activities such as movement and division.

What you'll learn in this topic

• The types of cellular activity that require energy.
• The relative energy costs of different cellular activities.

Your task is to help a cell acquire enough energy to survive and reproduce.