Which statement correctly compares a function of lipids to a function of proteins in the body?

• A. Both lipids and proteins primarily function as genetic information carriers.
• B. Lipids primarily serve as long-term energy storage molecules, while proteins function mainly as enzymes and structural components.
• C. Proteins are the main source of long-term energy storage, while lipids act as catalysts for biochemical reactions.
• D. Lipids and proteins both serve as the primary building blocks of nucleic acids.

Answer: (B)

Verified step by step guidance

1. Step 1: Begin by understanding the primary functions of lipids and proteins in the body. Lipids are primarily involved in long-term energy storage, insulation, and forming cell membranes. Proteins, on the other hand, serve as enzymes, structural components, signaling molecules, and transporters.
2. Step 2: Evaluate the first statement: 'Both lipids and proteins primarily function as genetic information carriers.' This is incorrect because genetic information is carried by nucleic acids (DNA and RNA), not lipids or proteins.
3. Step 3: Evaluate the second statement: 'Lipids primarily serve as long-term energy storage molecules, while proteins function mainly as enzymes and structural components.' This is correct because it accurately describes the roles of lipids and proteins in the body.
4. Step 4: Evaluate the third statement: 'Proteins are the main source of long-term energy storage, while lipids act as catalysts for biochemical reactions.' This is incorrect because lipids, not proteins, are the main source of long-term energy storage, and proteins, not lipids, act as catalysts (enzymes).
5. Step 5: Evaluate the fourth statement: 'Lipids and proteins both serve as the primary building blocks of nucleic acids.' This is incorrect because nucleic acids are composed of nucleotides, not lipids or proteins.