Which statement best explains why correct protein folding is critical for protein function and cellular health?

• A. A protein’s three-dimensional fold positions key side chains to form specific binding and catalytic sites; misfolding can cause loss of function and aggregation that damages cells.
• B. Correct folding is critical because only folded proteins can be translated by ribosomes; unfolded polypeptides cannot be synthesized.
• C. Correct folding is critical because it prevents peptide bond hydrolysis; misfolded proteins rapidly break down into free amino acids without enzymes.
• D. Correct folding is critical because it determines the amino acid sequence of the protein; misfolding changes the primary structure and therefore the gene’s coding sequence.

Answer: (A)