Which of the following macromolecules is primarily responsible for energy storage?

• A. Proteins
• B. Carbohydrates
• C. Nucleic Acids
• D. Water

Answer: (B)

Carbohydrates are primarily responsible for energy storage in living organisms. They serve as a quick and accessible source of energy due to their ability to be easily broken down into glucose, which can then be utilized for metabolic processes.

In the form of polysaccharides such as glycogen in animals and starch in plants, carbohydrates are stored for later use. When energy is needed, these complex carbohydrates can be hydrolyzed to release glucose. This stored energy is vital for maintaining physiological functions and supporting activities.

While proteins can also provide energy during prolonged periods without carbohydrates, their primary role is in the structure and function of cells rather than energy storage. Nucleic acids are primarily involved in genetic information storage and transfer, and water, although essential for life, does not serve as an energy storage molecule. Thus, carbohydrates are the macromolecules best suited for energy storage in biological systems.