Describe the role of water in a hydrolysis reaction. mention a specific hydrolysis reaction in the answer

Hydrolysis refers to the splitting of water. Water splits into hydrogen ion or proton (H⁺) and hydroxyl anion (OH⁻).

In biology, hydrolysis reaction is used to break down the covalent bond between two molecules by adding constituents of water molecule to them. It is exactly opposite of a condensation reaction.

The oxygen of the water molecule slowly forms the covalent bond with the reactant component. The hydrogen ions attach rapidly to other molecule.

It helps in digestion of food with the help enzymes such as proteases, nucleases, amylase etc which carry out hydrolysis reaction in order to break complex compounds into smaller units, energy production with the help of  ATP (adenosine triphosphate) hydrolysis etc.

The reaction of lactose hydrolysis is shown in the figure attached.

c. heat from the poles back down towards the equator.