| a secondary structure occurring in many proteins, consisting of several polypeptide chains running in parallel or alternating directions and joined by intermolecular hydrogen bonds, creating a flexible, strong arrangement. |
| beta structure n. A type of secondary structure of proteins in which several parallel polypeptide chains are cross-linked by intermolecular hydrogen bonds, resulting in a flexible, strong arrangement. Also called pleated sheet. |
| pleated sheet n. See beta structure. |