What are carbohydrates made up of primarily?

Carbohydrates are primarily composed of carbon, hydrogen, and oxygen. This composition is essential as it forms the basic structure of these biomolecules, which can vary from simple sugars (monosaccharides) to complex carbohydrates (polysaccharides). The typical ratio among these elements in carbohydrates follows the formula Cn(H2O)n, which emphasizes the combination of carbon and water—the very essence of sugars and starches, key energy sources for living organisms.

This molecular configuration is what enables carbohydrates to provide energy and serve structural roles in cells. Other elements specified in the other choices, such as nitrogen, sulfur, and phosphorus, are not the primary components of carbohydrates and are more relevant to other macromolecules like proteins, nucleic acids, and certain lipids. Thus, understanding the elemental makeup of carbohydrates reinforces the fundamental concepts of biochemistry and the classification of biological macromolecules.