. Carbohydrates like sugars and starches are made of only three elements: carbon (C), hydrogen (H), and oxygen (O). How is it possible that so many different carbohydrates can be formed using only these three elements? These elements are the least reactive in their family.

Different protons let these elements bond in a number of different ways.

Different combinations of the three elements result in different compounds.

These elements form long chains that keep growing, so the identity of each compound is always changing.