How does phenol denature proteins?
Phenol, or carbolic acid, will lower the pH. A hydrogen ion detaches itself from the molecules (this is basically what acidity is). Because of the increase in charged ions floating around the protein, they start to interact with the tertiary (and if applicable) quarternary structure bonds (e.g. ionic, hydrogen and disulphide bridges). As the bonds break it starts to unfold because the bonds were holding it together. With its three dimensional structure lost, the protein is denatured and no longer functions.
