Final answer:
The B-pleated sheet is a secondary structure in proteins, formed by hydrogen bonds between segments of amino acid residues. It is found in many proteins, including structural proteins like silk fibroin and enzymes like carboxypeptidase A and lysozyme.
Step-by-step explanation:
In biology, a B-pleated sheet is a secondary structure in proteins. It consists of pleats formed by hydrogen bonds between segments of amino acid residues on the polypeptide chain. The pleated segments align parallel to each other and are held together by hydrogen bonds between the same pairs of atoms on each aligned amino acid.
The B-pleated sheet is found in many globular and fibrous proteins. It is particularly important in structural proteins, such as silk fibroin, and can also be seen in portions of enzymes like carboxypeptidase A and lysozyme.