Monosaccharides (Glucose and Fructose)

Monosaccharides are the simplest form of sugar and the simplest unit of carbohydrates. Monosaccharides, often known as simple sugars, are the most basic carbohydrates. More complex carbohydrates, such as disaccharides and polysaccharides, are made up of them. Physically, they are  colourless, soluble in water, and appear as crystal-like substances.

Monosaccharides are composed of carbon, hydrogen, and oxygen atoms, as they are the simplest units of carbohydrates.

Monosaccharides are truly simple sugars because they exist as a single sugar unit that can be directly absorbed into your body after ingestion. Monosaccharides, unlike other carbs, do not need to be broken down during digestion, so when you eat a product that contains them, the sugars instantly enter your bloodstream, raising your blood sugar and delivering instant energy. Let’s discuss the Monosaccharides (glucose and fructose) study material, structure, and examples.

Monosaccharide Structure

The general formula for monosaccharides is (CH2O)n, which denotes a core carbon molecule linked to two hydrogens and one oxygen. The oxygen will also form a hydroxyl group when it bonds to hydrogen. Several of these carbon molecules can join together because carbon may create four bonds. A carbonyl group is formed when one of the carbons in the chain forms a double bond with oxygen. The monosaccharide belongs to the aldose family if this carbonyl occurs at the end of the chain. The monosaccharide belongs to the ketose family if the carboxyl group is in the centre of the chain.

Properties

Talking about the study material notes on Monosaccharides (glucose and fructose) in-depth, Monosaccharides are colourless, crystalline, water-soluble solids in their purest form. Because the orientation of the OH group interacts with the taste receptor on the tongue that detects sweetness, monosaccharides have a sweet flavour. Two monosaccharides can make a disaccharide, three to ten can form an oligosaccharide, and more than ten can form a polysaccharide via a dehydration reaction.

Functions

Within a cell, monosaccharides have two fundamental activities. They are utilised to store as well as generate energy. Glucose is a highly vital source of energy. When chemical bonds are disrupted, energy is released. Monosaccharides are also utilised as building blocks to create more complex sugars, which are structurally important.

Examples of Monosaccharide

• Glucose

Glucose is an essential monosaccharide because it gives many organisms energy and structure. Glucose molecules are broken down in glycolysis to provide energy and precursors for cellular respiration. When a cell does not require additional energy, glucose can be stored by mixing it with other monosaccharides. These lengthy chains are stored as starch by plants, which can be deconstructed and used as energy later. The polysaccharide glycogen, which can hold a lot of energy, is used by animals to store glucose chains.

• Fructose

It is a sugar that does not reduce. Sucrose is formed when fructose combines with glucose. Fructose is found in fruits like cherries. Fructose is commonly generated commercially from sugar cane, sugar beets, and corn. Annually, over 240,000 tonnes of crystalline fructose are produced. In all forms, including fruits and juices, fructose is widely added to foods and beverages to improve taste and brown various dishes, such as baked products. Excessive fructose consumption has been linked to insulin resistance, obesity, and high LDL cholesterol, which can contribute to type 2 diabetes and cardiovascular disease. You can refer to study material notes on Monosaccharides (glucose and fructose) to know about the fructose in detail!

• Galactose

Galactose is a monosaccharide that is produced by a variety of species, including mammals. Galactose is a sugar found in milk that mammals use to provide energy to their children. Lactose is formed when galactose and glucose are mixed. Lactose connections contain a lot of energy, and newborn mammals produce specific enzymes to break them apart. The enzymes that break lactose down into glucose and galactose monosaccharides are lost once a child is weaned from their mother’s milk.

• Metabolic Pathways that Include Monosaccharides

Monosaccharides play a significant role in a variety of metabolic pathways. These are some of the metabolic pathways:

• Glycolysis – the conversion of a monosaccharide to pyruvate, with the generation of high-energy biomolecules in the process
• Pentose phosphate pathway – a different metabolic pathway for breaking down glucose
• Gluconeogenesis – monosaccharide formation from non-carbohydrate precursors.
• Glycogenesis – the process of converting glucose to glycogen
• Fructose metabolism – Instead of glucose, fructose enters the glycolytic stream.
• Galactose metabolism – where galactose is phosphorylated and subsequently transformed into glucose-6-phosphate before entering the glycolytic pathway

Conclusion

Carbohydrates are aldehyde and ketone monomers and polymers with numerous hydroxyl groups attached. Although glucose and fructose are typical examples of simple sugars or monosaccharides, pentoses are another major type of monosaccharides. They have five carbons in their chain, and DNA and RNA include pentoses to some extent. An oligosaccharide becomes a polysaccharide when more than 20 monosaccharides are joined with glycosidic linkages. When you choose Monosaccharides (glucose and fructose) study material, you can see that thousands of monosaccharides can be found in some polysaccharides, such as cellulose.