Which type of biomolecule primarily functions as energy storage?

Carbohydrates are the primary biomolecules that function as energy storage in living organisms. When we consume carbohydrates, they are broken down into glucose, which is readily used by cells for energy. Excess glucose can be stored in the form of glycogen in the liver and muscle tissues for later use. Additionally, carbohydrates such as starch are important energy storage forms in plants.

Although proteins can serve as a source of energy, their primary role is structural and functional in tissues and cells. Nucleic acids, which include DNA and RNA, are primarily responsible for the storage and transmission of genetic information rather than energy storage. Vitamins are organic compounds that are essential for various metabolic processes but do not serve as energy-storage molecules themselves. Hence, carbohydrates stand out as the major biomolecule dedicated to energy storage among the given options.