A Level Biology Practice Exam

What characterizes a condensation reaction?

1. A reaction that releases carbon dioxide

2. A reaction resulting in the formation of a larger molecule with the release of water

3. A reaction involving the breakdown of complex molecules

4. A reaction that does not involve any energy changes

The correct answer is: A reaction resulting in the formation of a larger molecule with the release of water

The correct characterization of a condensation reaction is the formation of a larger molecule with the release of water. During this type of reaction, two smaller molecules combine to form a more complex molecule, typically resulting in the production of a water molecule as a by-product. This process is crucial in various biological contexts, such as the synthesis of macromolecules like proteins, carbohydrates, and nucleic acids. In contrast, reactions that release carbon dioxide are typically associated with processes like cellular respiration rather than condensation. The breakdown of complex molecules refers to hydrolysis reactions, which are the opposite of condensation, as they involve the addition of water to break down larger molecules. Lastly, the notion that condensation reactions do not involve energy changes is misleading; instead, they are often associated with the release of energy, which can drive the formation of larger molecules. Thus, understanding the nature of condensation reactions is essential in the broader context of biochemical processes.