Thiol reagents, such as 1,4-dithiothreitol (dtt), are often added to the solutions of such proteins to protect them from this reaction and to reverse it when it occurs. (the reverse reaction works best at slightly alkaline ph.) draw the product formed when dtt reacts with a protein disulfide bond to liberate the free thiol groups.

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.

the answer is option a.

the objects have the same charge.