Glucose and Fructose

Glucose and fructose, both are a type of sugar produced by living organisms. Glucose is an important sugar present in the human body, as it supplies the required energy to the human body. Before looking at the difference between glucose and fructose, let us learn more about glucose and fructose separately in detail. This article covers the importance of glucose and fructose and the bonds formed by them.

Glucose

An organism needs the energy to function and keep its basal metabolic rate at pace. This energy is produced from carbohydrates, especially glucose, produced from the food we consume.  This glucose is a hydrocarbon that produces energy in the form of Adenosine Triphosphate (ATP). This is the currency of energy to make our body function. This process has carbon dioxide as it’s a product, which is eliminated through our expiratory process in respiration. 

Glucose is present in plants as starch and amylopectin. This is present in animals in the form of glycogen. Glycogen and starch are complex hydrocarbons. These have glucose molecules as their subunits connected by glycosidic bonds. These glycosidic bonds are peculiar to sugar molecules as they can only be able to form these types of bonds. This is a monomer, and this is stored in our body as glycogen. 

The process of conversion of glycogen to glucose is called glycogenolysis. The production of glucose is called gluconeogenesis. Levels of glucose in our body are regulated by insulin and glucagon. Insulin reduces glucose in our body while glucagon corrects the state of low glucose. 

Even though diabetes is more detrimental, the state of hypoglycemia is an acute emergency, where a patient can enter into a state of comatose. As the brain needs glucose for functioning, a lack of catalyst to glucose function can result in hypoglycemia. The lack of insulin or resistance to insulin to other tissues is manifested as Diabetes mellitus. If diabetes occurs in young children due to chromosomal aberration, this is called diabetes insipidus. So for the functioning of our body, we need this form of energy called glucose. 

Fructose

Fructose is a monosaccharide sugar; this is seen concentrated in fruits and honey. This is a ketogenic sugar and when bonded through a glycosidic bond with glucose, another monosaccharide forms a disaccharide called sucrose. This is included in the dietary monosaccharide along with its co-members glucose and galactose. These three in combination give rise to different types of disaccharides. This is consumed in our diet as sucrose, in the intestine, it is broken down into fructose and glucose.

 This fructose is transported against the gradient, so it needs active transport. Many scientists state that fructose transport is carried out by GLUT transporters. This transport takes place from higher concentration in the intestinal lumen to lower concentration in cells, this transport requires GLUT5 and GLUT2 transporters. Fructose is absorbed more when it is given along with glucose in an equal ratio. So equally balanced sucrose gives increased absorption.

There is a taste called hydrogen breath test where if fructose is not absorbed properly it will be taken to the next stop, the large intestine where this fructose is fermented to produce hydrogen gas. This gas along with short fatty acids causes clinical symptoms such as belching, gastric pain, and bloating. This might mimic the symptoms of gastric ulcer or duodenal ulcer. This is also the currency of energy by ATP, this is through phosphorylation of fructose.

Detrimental effects of fructose include weight gain, there is an increase in low-density lipoprotein with a reduction of high-density lipoprotein causing risk factors for cardiovascular disease through an increase in bad fat. This causes a metabolic syndrome that includes diabetes and cardiovascular disease, where hyperlipidemia is prominent. Here the waist-hip ratio is high. This has a low glycemic index in comparison with its subordinate glucose and galactose. This before a meal can cause a low glycemic effect reflected in low postprandial blood sugar levels.

Difference between glucose and fructose:

Conclusion

Glucose is also called blood sugar because it is the primary sugar found in the blood. It is the body’s major source of energy. Blood carries glucose to all parts of the body. Whereas fructose enhances the metabolism of glucose. When glucose and fructose combine together it forms another sugar called sucrose, commonly called table sugar. In this article, we learned in detail about glucose, fructose, and their differences.