What is the difference among the alpha-helix and the beta-sheet protein conformations?
Alpha-helix and beta-sheet conformations are the two major types of secondary structure of a protein molecule. According to the primary protein structure its secondary structure can be of one type or the other.
In the alpha-helix structure the polypeptide curls longitudinally by the action of hydrogen bonds forming a spiral, or helix. In the beta-sheet conformation the protein is more distended and the hydrogen bonds form a zig-zag-shaped protein structure known as B-strand. Many assembled beta-strands make a beta-sheet.