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

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

Answer: (B)

Verified step by step guidance

1. Understand the role of enzymes in biological systems: Enzymes are specialized proteins that act as biological catalysts, meaning they 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 work by lowering this energy barrier, making reactions proceed more quickly and efficiently.
3. Eliminate incorrect options: (1) Enzymes are not structural components of cell membranes; that role is typically filled by lipids and proteins. (2) Enzymes do not provide energy for cellular processes; energy is usually provided by molecules like ATP. (3) Enzymes do not store genetic information; that is the role of DNA and RNA.
4. Focus on the correct function: The primary function of enzymes is to catalyze reactions by lowering the activation energy, which allows biological processes to occur at a rate necessary for life.
5. Conclude that the correct answer is: 'They speed up chemical reactions by lowering the activation energy.' This aligns with the fundamental role of enzymes in metabolism and other cellular processes.