The secondary structure of proteins is stabilized by:
Correct answer: B. Hydrogen bonds
- A. Ionic bonds
- B. Hydrogen bonds
- C. Disulfide bridges
- D. Hydrophobic exclusion
Explanation
Regular hydrogen bonding between backbone carbonyl and amide groups coils the chain into an alpha helix or folds it into a beta pleated sheet. Ionic bonds, disulphide bridges and hydrophobic exclusion all act between side chains and belong to the tertiary level instead. Being weak, these hydrogen bonds are the first to break on heating, which is why helices unwind during denaturation.
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About Proteins
Proteins are polymers of amino acids joined by peptide bonds, and their function depends on primary, secondary, tertiary and quaternary structure. The topic covers fibrous and globular proteins, enzymes, antibodies, hormones and transport proteins, as well as denaturation by heat or extreme pH.
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