Proteins themselves are made of chains of amino acids. There are only 20 amino acids used in life as we know it. The amino acids are to proteins as letters are to words. We have only 26 letters in the alphabet, but hundreds of thousands of words. Since proteins can be made of hundreds or thousands of amino acids, the protein possibilities are virtually limitless.
Proteins are often large, complex molecules.
The DNA that stores the genetic information. Mostly, it stores the instructions for making protein. The instructions for making proteins are a list of the amino acid sequences that make up a particular protein. A gene is the sequence for a particular protein. Proteins may be chains of hundreds of amino acids.