When a globular protein solution is slowly heated from 25 °C to 70 °C
CHEMISTRY · Single correct · A Level · Chemistry · Biomolecules · Biomolecules
Problem
When a globular protein solution is slowly heated from 25 °C to 70 °C, the tertiary structure collapses while the primary structure remains intact. Which statement best accounts for this observation?
(a) Heating supplies enough energy to cleave the peptide backbone but leaves weaker intermolecular forces unaffected
(b) The increase in temperature converts polar amino acids into nonpolar forms, eliminating hydrophobic interactions
(c) Noncovalent interactions such as hydrogen bonds and London dispersion forces are disrupted by thermal motion, but covalent peptide bonds are not broken at this temperature
(d) Thermal energy induces formation of additional covalent cross-links among side chains, forcing the protein to unfold