Question

Protein secondary structure is characterized by the pattern of hydrogen bonds between:

A. backbone amide protons and carbonyl oxygens.
B. backbone amide protons and side chain carbonyl oxygens.
C. side chain hydroxyl groups and backbone carbonyl oxygens.
D. side chain amide protons and backbone carbonyl oxygens.

Answer 1

Protein secondary structure consists of α-helix and β-pleated sheet conformations, stabilized by hydrogen bonds between atoms in the peptide backbone. These structures play a pivotal role in determining protein shape and function.

Step-by-step explanation:

The secondary structure of proteins refers to the local folding of regions within a polypeptide chain into organized structures like α-helix and β-pleated sheet, which are the most common forms. This folding is primarily stabilized by hydrogen bonds that occur between atoms in the peptide backbone, rather than the side chains. Specifically, in the α-helix, hydrogen bonds form between the oxygen atom in the carbonyl group of one amino acid and the hydrogen atom attached to the nitrogen in the amine group of another amino acid, which is typically four residues away.

tConversely, the β-pleated sheets consist of hydrogen bonds between carbonyl and amino groups of the backbone, but the sequences involved are longer and more extended than in the α-helix. These secondary structures are crucial, as they contribute significantly to the protein's overall shape and function.