Hello! The answer to your question would be as followed:
<u><em>Amino acids - a simple organic compound containing an amino and carboxyl</em></u>
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<u><em>Polypeptides - a linear organic polymer consisting of a large number of amino-acid residues bonded together in a chain, forming part of (or the whole of) a protein molecule.</em></u>
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<u><em>Proteins - Polymers of amino acids</em></u>