Question

in the secondary structure of proteins, hydrogen bonds between amino acids create: a side groups b alpha helixes and beta-pleated sheets c disulfide bridges d van der waals interactions e all of the above

Explanation:

• Option A: Side groups (R - groups) of amino acids are part of the primary structure's amino acid composition and not formed by hydrogen bonds in secondary structure.
• Option B: In protein secondary structure, hydrogen bonds between the backbone atoms of amino acids (not side groups) form alpha - helices (where the polypeptide chain coils) and beta - pleated sheets (where polypeptide chains are aligned side - by - side). This matches the role of hydrogen bonds in secondary structure.
• Option C: Disulfide bridges are covalent bonds between cysteine residues and are involved in tertiary (and sometimes quaternary) structure, not formed by hydrogen bonds in secondary structure.
• Option D: Van der Waals interactions are weak intermolecular forces that contribute to tertiary and quaternary structure, not a result of hydrogen bonds in secondary structure.
• Option E: Since A, C, and D are incorrect, this option is also incorrect.

Answer:

B. Alpha helixes and beta - pleated sheets