When a protein is denatured, why does it lose its functionality?

• A. Denaturation breaks the covalent bonds that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function.
• B. Denaturation destroys the primary structure of the protein, and the protein breaks down to monomers.
• C. Different amino acids are substituted into the sequence, so the protein's properties change.
• D. The protein's pH changes, and the change causes the protein to lose its functionality.
• E. Denaturation breaks the intramolecular bonds, such as hydrogen bonds and van der Waals interactions, that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function.