Answer:
c. amino acids
Step-by-step explanation:
Amino acids are the monomers of proteins. Two amino acids combine in a condensation reaction that releases water forming a peptide bond. These two amino acid residues form a dipeptide. If a third amino acid is bound, a tripeptide is formed and so on to form a polypeptide.
The amino acids are formed by an alpha carbon attached to a carboxyl group, an amino group, a hydrogen and an R chain of variable composition, which determines the properties of the different amino acids; There are hundreds of R chains so hundreds of different amino acids are known. In natural amino acids, the amino group and the carboxyl group are attached to the same carbon that is called asymmetric alpha.
The binding of several amino acids results in chains called polypeptides or simply peptides. Protein will be discussed when the polypeptide chain exceeds 50 amino acids or the total molecular weight exceeds 5,000 amu. There are about 20 different amino acids composing proteins. The chemical binding between amino acids in proteins occurs through a peptide bond. This reaction occurs naturally in ribosomes, both of the endoplasmic reticulum and the cytosol.