The cell can be thought of as a system. A system usually consists of many parts that work together. A system will not function as well if
one part is not working properly. We as humans use systems every
day, such as a bicycle. Some of the parts in your bike are the gears,
the brakes, and the materials used to make the bike frame. What
would happen to a bicycle if one of the parts, such as the brakes,
stopped working?