Question

which repeating unit makes up a protein?
peptide acids
carboxylic acids
fatty acids
amino acids

Explanation:

Proteins are polymers made up of amino - acid monomers linked by peptide bonds. Peptide acids is not a correct term. Carboxylic acids are a general class of organic compounds and not the repeating unit of proteins. Fatty acids are components of lipids, not proteins.

Answer:

amino acids