Final answer:
Protein hydrogen bonds between amino acids help maintain the secondary structure of proteins, such as the alpha-helix and beta-pleated sheet.
Step-by-step explanation:
Protein hydrogen bonds between amino acids help maintain the secondary structure of proteins. The secondary structure refers to the regular structures formed by proteins through intramolecular hydrogen bonding between the oxygen atom of one amino acid and the hydrogen attached to the nitrogen atom of another amino acid. The most common secondary structures are the alpha-helix and beta-pleated sheet. In the alpha-helix structure, the helix is held together by hydrogen bonds between the oxygen atom in a carbonyl group of one amino acid and the hydrogen atom of the amino group that is just four amino acid units farther along the chain.
In the beta-pleated sheet, the pleats are formed by similar hydrogen bonds between continuous sequences of carbonyl and amino groups that are further separated on the backbone of the polypeptide chain.