Carbohydrates consist of which elements in a specific ratio?

Carbohydrates are organic compounds that play essential roles in biological systems. They consist of three primary elements: carbon, hydrogen, and oxygen. The defining feature of carbohydrates is their elemental ratio, specifically that for every carbon atom in the molecule, there are typically two hydrogen atoms and one oxygen atom. This structural formula can be noted as a ratio of 1:2:1 for carbon, hydrogen, and oxygen respectively.

This ratio is key to classifying different carbohydrates, such as monosaccharides (like glucose), which adhere to this molecular structure. In polysaccharides, although the structure becomes more complex due to the linking of these monosaccharides, the fundamental ratio of elements remains the same.

Understanding this ratio clarifies the distinction between carbohydrates and other types of biological macromolecules, which typically have different elemental compositions. Other options do not accurately represent the composition of carbohydrates, focusing instead on unrelated elements or incorrect ratios that do not apply to this class of biomolecules.