Question

Environmental condition affect protein folding. Which of the following is false?

Extreme temperatures would denature a protein extracted from the human body.

  

Ionic bonds are sensitive to changes in pH

   

Hydrogen bonds are sensitive to temperature.

  

The primary structure of a protein is sensitive to temperature and pH.

Enzymes are often unable to function at extreme temperatures or pHs because they would be denatured.

Answer 1

changes in pH lead to changes in ionization of different groups on proteins. So, ionic bonds are highly sensitive to changes in pH. Also, extreme temperatures, much higher than the optimum temperature for the protein would affect the interactions that hold the secondary and tertiary structures of proteins and so denature them. This denaturation would inactivate enzymes as well. However, there are few proteins, isolated from thermophilic organisms that are able to withstand high temperatures, such as the Taq DNA polymerase obtained from Thermus aquaticus.

Hydrogen bonds are governed by the internal energy of the molecules and so are extremely sensitive to changes in temperature.

However, the primary structure of proteins does not change due to changes in pH or temperature due to the stability of peptide bonds.