Question

secondary structure is caused by which of the following? hydrogen bonding between groups along the backbone. specific types of peptide bonds hydrogen bonds between the r groups multiple polypeptides interacting with each other

Explanation:

The secondary structure of proteins is formed by hydrogen - bonding between groups along the polypeptide backbone, like the carbonyl oxygen and amide hydrogen atoms. Peptide bonds form the primary structure. Hydrogen bonds between R - groups contribute to tertiary structure. Interaction of multiple polypeptides is quaternary structure.

Answer:

Hydrogen bonding between groups along the backbone.