* Amino acids are the building blocks of proteins. Proteins are complex molecules that play a vast array of roles in living organisms.

* Not all complex molecules are made of amino acids. There are many other types of complex molecules, such as carbohydrates, lipids (fats), and nucleic acids (DNA and RNA), which are made of different building blocks.

Here's a breakdown:

* Proteins: Composed of chains of amino acids linked together.

* Carbohydrates: Made up of simple sugars (like glucose) linked together.

* Lipids: Made up of fatty acids and glycerol.

* Nucleic acids: Composed of nucleotides, which contain a sugar, a phosphate group, and a nitrogenous base.

So, while amino acids are essential building blocks for a very important class of complex molecules (proteins), they don't represent the building blocks of all complex molecules.