Which of the following best describes the primary function of enzymes in biological systems?

• A. They speed up chemical reactions by lowering the activation energy.
• B. They store genetic information.
• C. They serve as structural components of cell membranes.
• D. They provide energy for cellular processes.

Answer: (A)

Verified step by step guidance

1. Understand the role of enzymes in biological systems: Enzymes are biological catalysts that speed up chemical reactions without being consumed in the process.
2. Recall the concept of activation energy: Activation energy is the minimum amount of energy required for a chemical reaction to occur. Enzymes lower this energy barrier, making reactions proceed faster.
3. Eliminate incorrect options: Enzymes do not store genetic information (this is the role of DNA and RNA), nor do they serve as structural components of cell membranes (this is the role of lipids and proteins). Enzymes also do not directly provide energy for cellular processes (this is the role of molecules like ATP).
4. Focus on the correct function: The primary function of enzymes is to catalyze reactions by lowering the activation energy, which increases the reaction rate.
5. Conclude that the correct answer is: 'They speed up chemical reactions by lowering the activation energy.'