Proteins are the largest macromolecules in biology, found throughout every cell. They are also the most adaptable organic molecule in living system and is found in a many various kinds that range in size from small polymers to huge peptides. Proteins are polymers composed of amino acids, which are connected by peptide bonds. Proteins, the protein building blocks are the naturally occurring twenty amino acids. Proteins are, therefore, the multimers made up of amino acids.