What are carbohydrates primarily composed of?

Carbohydrates are primarily composed of carbon, hydrogen, and oxygen, which is the basis for their classification as organic compounds. The general molecular formula for carbohydrates can often be represented as Cn(H2O)n, indicating that for every carbon atom, there are typically water molecules composed of hydrogen and oxygen.

This composition is key to understanding the structure and function of carbohydrates, which include sugars and starches that serve vital roles in energy storage and supply, as well as structural components in cells. For instance, glucose, a simple sugar, is a fundamental carbohydrate that provides energy to cells, and cellulose, a complex carbohydrate, is important for the structural integrity of plant cell walls.

The other choices do not accurately reflect the primary composition of carbohydrates. For instance, nitrogen is not a constituent of carbohydrates, as it is typically associated with proteins and nucleic acids. Sulfur is also not part of carbohydrates and is generally found in certain amino acids and vitamins. Similarly, phosphorus is primarily relevant in nucleic acids and energy carriers like ATP, not carbohydrates.