The monomer or base unit for proteins is called an amino acid. Amino acids are organic molecules that serve as the building blocks of proteins.
Each amino acid contains a central carbon atom, an amino group (–NH2), a carboxyl group (–COOH), a hydrogen atom, and a variable side chain known as the R group. The R group determines the specific characteristics and functions of each amino acid.
Proteins are formed when amino acids link together through peptide bonds, creating long chains. The sequence and arrangement of these amino acids ultimately dictate the structure and function of the protein. There are 20 different amino acids that can be combined in various sequences to create a vast array of proteins, each with unique functions in living organisms.