A Level Biology Practice Exam

Which statement accurately describes hydrolysis in terms of molecular breakdown?

1. It produces one large molecule

2. It requires the addition of a water molecule

3. It occurs without any energy change

4. It is the same as condensation reactions

The correct answer is: It requires the addition of a water molecule

Hydrolysis is a biochemical process where a water molecule is used to break down a larger molecule into smaller components. This reaction is essential in various biological pathways, particularly in the digestion of macromolecules such as proteins, carbohydrates, and lipids. During hydrolysis, the addition of water helps to cleave specific bonds within the larger molecule, resulting in the formation of two or more smaller molecules. This process showcases water's crucial role as a reactant needed for the breakdown of complex compounds. The other options do not accurately represent hydrolysis. The formation of a single large molecule, the absence of energy changes during the process, and the similarity to condensation reactions all mischaracterize the nature and function of hydrolysis in molecular breakdown. In contrast, hydrolysis is specifically defined by the addition of water, making the accurate choice stand out clearly.