Advanced Placement (AP) Biology Practice Exam

What is the process known as hydrolysis?

1. Building larger molecules

2. Breaking down complex molecules to simpler compounds

3. Creating energy storage molecules

4. None of the above

The correct answer is: Breaking down complex molecules to simpler compounds

Hydrolysis is a chemical process in which water is used to break down a compound. It typically involves the cleavage of bonds in a larger molecule, resulting in the formation of simpler molecules or monomers. This process is crucial in biological systems, particularly in digestion, where complex macromolecules such as proteins, carbohydrates, and lipids are broken down into their constituent parts (amino acids, simple sugars, and fatty acids, respectively). During hydrolysis, a water molecule is added to facilitate the reaction, allowing the chemical bonds in the larger molecule to break. This is essential for the body to utilize nutrients, as these simpler compounds can be more easily absorbed and used for energy or as building blocks for other biological molecules. By contrast, the other options describe processes that are not associated with hydrolysis. For example, building larger molecules would refer to dehydration synthesis, while creating energy storage molecules does not encapsulate the breakdown aspect of hydrolysis.