How the heart pumps blood. Video

For most of history, scientists weren't quite sure why our hearts were beating or even what purpose they served. Eventually, we realized that these thumping organs serve the vital task of pumping clean blood throughout the body. This video investigates how it all works by taking a closer look at the heart's highly efficient ventricle system.
 

The Calvin Cycle of Energy Video

A hearty bowl of cereal gives you the energy to start your day, but how exactly did that energy make its way into your bowl? It all begins with photosynthesis, the process that converts the air we breathe into energizing glucose. This video details the highly efficient second phase of photosynthesis -- called the Calvin cycle -- which converts carbon dioxide into sugar with some clever mix-and-match math.

Sugar is Everywhere Video

While sugar is easy to spot in candy, soft drinks, and ice cream, it also hides out in foods you might not expect.  This video decodes confusing labels and sugar's many aliases to help determine just how much of that sweet carbohydrate makes its way into our diets.