Aprotein is composed of a long chain of monomers called?

Answer;

Amino acids

Explanation;

-Amino acids are the monomers used to build the chains that eventually become proteins. There are approximately 20 - 22 different common amino acids. They are joined together in long chains by chemical reactions that eliminate water and create joins between them called peptide bonds.

-When joining two amino acids together cells carry out a chemical reaction between the amine group of one amino acid and the carboxylic acid group of the second amino acid. A molecule of water is eliminated during this reaction which is called a condensation reaction or a dehydration synthesis.

-Two amino acids linked together in his way is called a dipeptide and a long chain of amino acids is called a polypeptide.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.