What distinguishes fructose from glucose in terms of chemical structure?

Fructose and glucose are both simple sugars, but they have distinct chemical structures that set them apart from each other. The primary difference between them lies in their configurations.

Fructose is a ketose sugar, meaning it has a ketone group (C=O) at the second carbon atom, while glucose is an aldose sugar with an aldehyde group (C=O) at the first carbon atom. This difference in the position of the carbonyl group leads to variations in their molecular structures and, as a result, their physical properties as well.

These configuration differences also cause them to have unique sweetness profiles and metabolic pathways in the body. While they may both have the same molecular formula (C6H12O6), the distinct arrangements of atoms in their molecular structure define their identity and physiological roles.

Although options related to molecular weight, functional groups, and solubility might have some relevance in broader discussions of carbohydrates, they do not specifically identify the crucial structural difference that distinguishes fructose from glucose as effectively as configuration does.