Which of the following is the most accurate statement regarding the functions of proteins?

• A. Proteins serve as enzymes, structural components, transporters, and play roles in cell signaling.
• B. Proteins function exclusively as hormones in biological systems.
• C. Proteins are primarily used for long-term energy storage in cells.
• D. Proteins are the main genetic material in all living organisms.

Answer: (A)

Verified step by step guidance

1. Understand the role of proteins in biological systems: Proteins are versatile macromolecules that perform a wide range of functions, including acting as enzymes, structural components, transporters, and signaling molecules.
2. Evaluate the first statement: Proteins serve as enzymes, structural components, transporters, and play roles in cell signaling. This is accurate because proteins are involved in catalyzing biochemical reactions, providing structural support (e.g., collagen), transporting molecules (e.g., hemoglobin), and facilitating communication between cells (e.g., insulin).
3. Analyze the second statement: Proteins function exclusively as hormones in biological systems. This is incorrect because proteins have diverse functions beyond hormones, such as enzymatic activity and structural roles.
4. Examine the third statement: Proteins are primarily used for long-term energy storage in cells. This is incorrect because lipids, not proteins, are the primary molecules used for long-term energy storage.
5. Review the fourth statement: Proteins are the main genetic material in all living organisms. This is incorrect because DNA and RNA are the main genetic materials, not proteins.