Glucose and fructose are both monosaccharides, which are simple sugars and the most basic units of carbohydrates. Although they share the same molecular formula C6H12O6 , their structures and the arrangement of their atoms differ, resulting in different properties and metabolic pathways in the human body.Structural Differences:1. Glucose is an aldohexose, meaning it has an aldehyde functional group -CHO at the end of the molecule. Fructose, on the other hand, is a ketohexose, containing a ketone functional group >C=O within the molecule.2. In their ring forms, glucose forms a six-membered pyranose ring, while fructose forms a five-membered furanose ring. The ring forms are the most stable and predominant forms in aqueous solutions.Metabolic Implications:1. Glucose and fructose are metabolized differently in the human body. Glucose is primarily metabolized in various tissues, including the liver, muscles, and brain. It is the primary energy source for cells and is regulated by insulin, which helps transport glucose into cells. In contrast, fructose is primarily metabolized in the liver, where it is converted into glucose, glycogen, lactate, or fat. Fructose metabolism is not regulated by insulin.2. Since fructose is metabolized in the liver, it does not cause an immediate spike in blood sugar levels like glucose does. However, excessive consumption of fructose can lead to increased fat production and storage in the liver, which may contribute to non-alcoholic fatty liver disease, insulin resistance, and increased risk of type 2 diabetes and cardiovascular diseases.3. The different metabolic pathways of glucose and fructose also affect satiety and hunger signals. Glucose consumption leads to the release of insulin and other hormones that promote satiety, while fructose does not have the same effect, potentially leading to increased calorie intake and weight gain.In summary, glucose and fructose differ in their chemical structures, with glucose being an aldohexose and fructose being a ketohexose. These structural differences result in distinct metabolic pathways in the human body, with glucose serving as the primary energy source for cells and fructose being primarily metabolized in the liver. The different metabolic pathways have implications for blood sugar regulation, fat storage, and satiety signals.