Here's a breakdown of the three key components:

1. Amino Acids: These are the building blocks of proteins. There are 20 different types of amino acids, and they are linked together in specific sequences to create different proteins.

2. Peptide Bonds: Amino acids are joined together by peptide bonds. These bonds form between the carboxyl group of one amino acid and the amino group of another amino acid.

3. Polypeptide Chains: When multiple amino acids are linked together by peptide bonds, they form a long chain called a polypeptide chain. Proteins can be made up of one or more polypeptide chains.

So, to summarize:

* Proteins are made of amino acids.

* Amino acids are linked by peptide bonds.

* The resulting chain is called a polypeptide chain.