Answer: Amino acids; peptide
Step-by-step explanation:
20 different AMINO ACIDS link together to form chains. A protein is composed of one or more of these PEPTIDE chains which are twisted and folded into a particular shape.
There exists 20 amino acids capable of forming protein in the Human body. At least two amino acids are joined together by a peptide bond to form polypeptide chains that are then held together by hydrogen bonds in twisted alpha helical structures to form proteins.