Question

An atom in an amino acid that is responsible for hydrogen bonding in polypeptides. (2 answers)

Answer 1

The hydrogen bonds are formed between atoms in the

the peptide bond (CO and NH2)

peptide bond atoms and R group atoms (CO or NH2 with Side chain of amino acid)

between R groups (Side chain to side chain)

The carbonyl oxygen and an amine hydrogen involved in the hydrogen bond formation in the peptide bond. These hydrogen bonds occur at regular intervals of one hydrogen bond every fourth amino acid alpha helix structure of the protein and these hydrogen bonds are called as internal hydrogen bonds. Same way in beta-sheet the hydrogen bonds are formed between atoms of two strands called inter hydrogen bonds.

Sometimes between R groups or side chains like serine OH group participate in hydrogen bonding to another serine OH group within the polypeptide.