A Level Biology Practice Exam

What is the purpose of hydrolysis in biological systems?

1. To build larger molecules

2. To break down molecules into smaller components

3. To create energy directly

4. To store nutrients

The correct answer is: To break down molecules into smaller components

Hydrolysis plays a crucial role in biological systems primarily for breaking down larger molecules into smaller, more manageable components. This process involves the addition of water to chemical bonds, which helps to cleave these bonds and facilitate further metabolic reactions. For example, during digestion, complex carbohydrates, proteins, and fats are hydrolyzed into simple sugars, amino acids, and fatty acids, respectively. This breakdown allows cells to utilize these smaller molecules for energy, synthesis of new compounds, or for various cellular functions. In contrast, the other options describe different processes: building larger molecules is generally associated with dehydration synthesis; creating energy directly is usually linked to processes like cellular respiration; and nutrient storage involves processes like the synthesis of glycogen or triglycerides rather than hydrolysis itself. The focus of hydrolysis on breaking down molecules emphasizes its essential role in metabolism and energy production in living organisms.