Advanced Placement (AP) Biology Practice Exam

Which process is essential in synthesizing larger biological molecules?

1. Anabolic reactions always breaking down macromolecules.

2. Dehydration synthesis is crucial in this process.

3. Hydrolysis is critical for linking small units together.

4. It primarily occurs in the presence of oxygen only.

The correct answer is: Dehydration synthesis is crucial in this process.

Dehydration synthesis, also known as condensation reaction, is the process that plays a crucial role in synthesizing larger biological molecules, such as carbohydrates, lipids, proteins, and nucleic acids. This process involves the removal of a water molecule (hence "dehydration") as two smaller molecules are covalently bonded together, facilitating the formation of a larger macromolecule. For example, when two monosaccharides undergo dehydration synthesis, they form a disaccharide, with a water molecule released in the process. The significance of dehydration synthesis in building complex biomolecules is foundational to biological chemistry, as it not only creates larger structures but also contributes to the diversity and functionality of macromolecules in living organisms. Understanding this process gives insight into how cells construct the necessary components for life and metabolism, which is essential for topics like metabolism and cellular processes in AP Biology.