posted by Laura .
What is the difference between an amino acid and a protein?
How does this difference in structure affect biological function?
A protein is a long chain of amino acids linked together by "peptide links". It is a biological polymer molecule. Body tissues are made of proteins, not individual amino acids which would not give them the structural strength they need.
The chemical functions of proteins, especially enzymes , depend on the 3-dimensional structure of proteins that cannot be duplicated by little molecules such as amino acids.