What is the difference in the bonding between alpha-helix and beta sheets?
Answers
To add to Mr. Abassi’s answer—or to simplify—the alpha helix and the beta sheet are secondary protein structures. The alpha helix is a polypeptide chain that is rod-shaped and coiled in a spring-like structure, held by hydrogen bonds. A helix can be left-handed (beta) or right-handed where the alpha helix is always right-handed.
Beta pleated sheets are made of beta strands connected laterally by two or more hydrogen bonds forming a backbone. Each beta strand, or chain, is made of 3 to 10 amino acid residues. The chains are aligned side-by-side with every other chain situated opposite the other. These are also held together by hydrogen bonds, but the bonds in the beta sheet are inter-molecular, occurring outside the chain—connecting the two (or more) chains—while those of the alpha helix are intra-molecular, only occurring within the chain itself.
Alpha helices and beta pleated sheets are the two most common secondary protein structures. Both can be present in the same molecule. A good comparison of the two can be found here: Difference Between Alpha Helix and Beta Pleated Sheet
Answer:
In an α helix, the carbonyl (C=O) of one amino acid is hydrogen bonded to the amino H (N-H) of an amino acid that is four down the chain. ... In a β pleated sheet, two or more segments of a polypeptide chain line up next to each other, forming a sheet-like structure held together by hydrogen bonds.