Differences between alpha helix and beta pleated sheet structures of proteins?

Question

William Albracht · Accepted Answer

The difference between these examples of secondary protein structure is the shape.

An alpha helix is a spiral shaped portion of a protein molecule. Imagine a twisting ribbon to imagine the shape of the alpha helix.

A pleated sheet (also called a #beta# pleated sheet) looks like a piece of paper which had been folded in an alternating pattern like when you make a fan.

![https://tutor.hix.ai)

A long chain of amino acids will have some regions which will twist to form alpha helices and other regions which will take on a pleated sheet shape. This is important because the two types of shapes combine to give the protein its shape; and the shape of a protein determines the job it will do!

This video discusses proteins from 10:14 to 13:30. Topics include protein structure and function including the four levels of protein structure.

Hope this helps!

Michael Adams · Answer

undefined The beta pleated sheet structure is made up of amino acid strands that run alongside each other and form hydrogen bonds between adjacent strands; the alpha helix is more compact and rigid, whereas the beta pleated sheet is more flexible and can form either parallel or antiparallel arrangements. The alpha helix structure is a right-handed coil formed by hydrogen bonding between the carbonyl oxygen atom of one amino acid and the amide hydrogen atom of another.