This video describes the structural features of beta pleated sheet which is one type of secondary structure of protein. The beta sheet, (βsheet) (also βpleated sheet) is a common motif of the regular protein secondary structure. Beta sheets consist of beta strands (βstrands) connected laterally by at least two or three backbone hydrogen bonds, forming a generally twisted, pleated sheet. A βstrand is a stretch of polypeptide chain typically 3 to 10 amino acids long with backbone in an extended conformation. The supramolecular association of βsheets has been implicated in the formation of the fibrils and protein aggregates observed in amyloidosis, notably Alzheimer's disease.