Question

You treat a protein with the denaturant urea. For each interaction or bond below, state if the interaction or bond is disrupted by the urea treatment.

(a) Disulfide bonds
(b) Hydrogen bonds
(c) Van der Waals forces
(d) Ionic bonds

Answer 1

Urea disrupts hydrogen bonds, van der Waals forces, and ionic bonds in proteins, but it does not directly disrupt disulfide bonds. Option (a) Disulfide bonds is the correct answer.

Step-by-step explanation:

When treating a protein with the denaturant urea, various stabilizing interactions can be disrupted. Urea is known to disrupt hydrogen bonds, which are crucial for maintaining the secondary and tertiary structures of proteins.

However, urea does not directly disrupt disulfide bonds, instead, it disrupts the residues that come close due to protein folding. Urea also disrupts van der Waals forces, which are weak interactions that play a role in stabilizing tertiary structures.

Lastly, ionic bonds, also known as salt bridges, can be disrupted by urea because it can interfere with the electrostatic interactions between charged amino acid side chains.

In conclusion, the correct option is that urea treatment disrupts hydrogen bonds, van der Waals forces, and ionic bonds but does not directly disrupt disulfide bonds.