The human body produces about 1.7 liters of saliva a day to aid in digestion. The digestive systems of different organisms are examined in a video that follows the digestive path, beginning with acids, moves to the importance of...

Get an overview of three of the key macromolecules of life (proteins, fats, and carbohydrates), and how they get digested and absorbed.

Behind every fart (and poop) is an army of gut bacteria undergoing some crazy (and crazy useful) biochemistry. Learn what they have in common with beer brewing, and why we'd want to know about this science anyway. [4:53]