Proteins include a diversity of structures resulting in a wide range of functions. Important part of our cells and they help us to function and survive. Enzymatic proteins regulate metabolism by acting as catalysis, chemical agents that selectively speed up chemical reactions without being consumed by the reaction. Are considered workhorses that keep the cell running because they can perform processes over and over again. Humans have thousands of proteins, each have their own known molecules and specific functions. All made of the same set of 20 amino acids, linked in unbranched polymers. Peptide bond: the bond between amino acids. Protein: a biologically functional molecule made up of one or more polypeptides, each folded and coiled into a specific 3d structure. All amino acids share a common structure. Amino acid: an organic molecule with both and amino group and a carboxyl group. The centre of the amino acid there is an asymmetric carbon atom called the alpha carbon.